Earnings release
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Page 1 of 32 Highlights Nova Scotia Gold Projects Development • St Barbara approved the Final Investment Decision to proceed with the Touquoy Restart following the approval of amendments to the Touquoy Industrial Approval permit conditions: o The mining contractor commenced mobilisation to site in June; o All long-lead time items have been procured and other preparations are on track; and o Recruitment is underway, with official reopening targeted for November 2026. • The 15-Mile Processing Hub initial project description was submitted to the Impact Assessment Agency of Canada in June for a decision on the permitting pathway. • St Barbara is targeting a Final Investment Decision in mid-2027; and • An updated Mineral Resources Estimate of 62.4 Mt @ 1.2 g/t Au containing 2.5 Moz Au (up 0.5Moz or 24%) was announced on 28 July 2026, subsequent to the quarter end. New Simberi Gold Project Development • St Barbara and Lingbao Gold Group approved the Final Investment Decision to proceed with the US$333 million expansion of the New Simberi Gold Project: o Construction is well underway with earthworks for the main laydown and Run-of-Mine pad areas nearing completion; o New ball mill is due to depart China in early August for delivery to site in early October; and o Engineering design for the grinding circuit is 50% complete, with procurement also 50% complete. • Exploration drilling below the current Samat sulphide Ore Reserve returned encouraging results, including: o SDH725: 7 m @ 5.8 g/t Au from 86 m; and o SDH727: 4 m @ 6.4 g/t Au from 47 m. • New Simberi growth capital investment (100% basis) was A$22 million for Q4 June FY26. Operating Performance • Total Recordable Injury Frequency Rate for New Simberi at the end of Q4 June FY26 was 0.4 per million hours worked, compared to 0.5 at the end of Q3 March FY26. • New Simberi cash flow contribution for Q4 June FY26 was A$29 million (100% basis). • New Simberi production for Q4 June FY26 was 14,658 ounces (up 8% compared to Q3 March FY26) at an AISC of A$4,514 per ounce. Gold production for H2 FY26 of 28,180 ounces was up 39% on H1 FY26. • Attributable gold production from New Simberi for Q4 was 7,329 ounces (i.e. 50% of 14,658 total ounces) coming in ahead of updated guidance of 5,600 to 6,800 ounces (i.e. 40% of 14,000 to 17,000 ounces). Financial Strength • New Simberi sales for Q4 June FY26 totalled 13,399 ounces at an average realised price of A$6,314 per ounce. St Barbara’s attributable gold sales were 6,700 ounces for Q4 June FY26, with a further 187 ounces sold at A$6,572 per ounce from the gold recovery work at the Touquoy processing plant. • As at 30 June 2026 St Barbara’s cash balance was A$475 million. Attributable cash and gold bullion across New Simberi Gold Group was a further A$21 million. Listed investments were another A$13 million. • St Barbara remains fully funded to meet the upcoming capital expenditure requirements for the Touquoy Restart, the expansion of New Simberi and development of the 15-Mile Processing Hub Project. Q4 June FY26 3 months to 30 June 2026 (unaudited)
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St Barbara Quarterly Report / Q4 June FY26 Page 2 of 32 St Barbara Managing Director and CEO Andrew Strelein said: “This has been a transformational quarter for St Barbara. At Nova Scotia, we approved the Final Investment Decision for the Touquoy Restart, with the mining contractor mobilising to site and processing on track to recommence by the end of calendar 2026. The 15-Mile Processing Hub Project permitting has advanced and more recently we have confirmed a 24% increase in Mineral Resources to 2.5 million ounces. At New Simberi, construction of our US$333 million expansion with Lingbao Gold Group is progressing well, with earthworks, the ball mill delivery and the new wharf all advancing to schedule. Importantly, we remain financially strong, with A$509 million in cash, gold and investments, leaving St Barbara fully funded to deliver all three growth projects. New Simberi’s operational performance continued to improve, as the operation increased production again and delivered cashflow to the business.” Development Projects Nova Scotia Project Development Touquoy Restart The Touquoy Restart project full Final Investment Decision ( “FID”) was approved during the quarter and is on track to recommence processing of the remaining medium and low -grade ore stockpiles by the end of calendar year 2026. All long-lead items have been ordered and refurbishment of the processing plant is underway in preparation for commissioning. Preparation for the in- pit tailings deposition system and decant water infrastructure is underway. Material movement activities have already commenced on the ore and waste stockpiles to support tailings cover reclamation requirements and to prepare ore stockpiles for haulage to the process plant. Recruitment and onboarding activities for the Touquoy Restart are progressing well with the welcome return of many employees who were part of previous operations. 15-Mile Processing Hub Project The 15-Mile Processing Hub P roject has commenced the permitting process with the submission of the Initial P roject Description (“IPD”) to the Impact Assessment Agency of Canada (“IAAC”) as announced on 19 June 20261. The central 15-Mile Processing Hub processing facility will comprise the relocated Touquoy processing equipment, supplemented by a new larger ball mill together with new associated infrastructure including a tailings management facility . Ore will be sourced from the four open pits at the 15-Mile Mine and from ore trucked from two satellite operations – an open pit at the Old Austen Mine (formerly Beaver Dam) and an open pit at the Old Mitchell Mine (formerly Cochrane Hill). The three sites have been substantially redesigned to incorporate feedback from First Nation communities, local stakeholders, regulators and environmental experts while incorporating substantial design improvements. An updated Mineral Resources Estimate has been completed to support the next phase of the 15-Mile Processing Hub Project, as announced on 28 July 2026 2. The new Mineral Resources Estimate incorporates updated geological interpretations, a revised estimation methodology and additional historical drilling data. St Barbara’s Mineral Resources Estimate has previously employed Multiple Indicator Kriging (MIK) as the basis of estimation considered to be most appropriate for the validated drilling database and geological confidence available at the time. Th e comprehensive validation and verification of historical drilling data has enabled this data to be incorporated into the resource database, considerably increasing the available data for estimation across all deposits. The enhanced data density has supported the application of Ordinary Kriging (OK) estimation basis because of the increased confidence in the interpretation of mineralisation geometry and continuity supporting the modelling of constrained geological wireframes. The Mineral Resources Estimate has been expanded by 24%, or 0.5 Moz, to 62.4 Mt @ 1.2 g/t Au containing 2.5 Moz Au (including 56.3 Mt @ 1.2 g/t Au containing 2.3 Moz Measured and Indicated). 1 Refer to ASX announcement dated 19 June 2026 titled “Permitting Commences for 15-Mile Processing Hub” 2 Refer to ASX announcement dated 28 July 2026 titled “15-Mile Processing Hub Mineral Resources Estimate Increases 24% to 2.5 Moz”
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St Barbara Quarterly Report / Q4 June FY26 Page 3 of 32 Combined Nova Scotia Projects Outlook The anticipated timeline for the Touquoy Restart and the 15-Mile Processing Hub Project remains on t rack with the Company’s announcement of 20 April 2026. The anticipated timeline is shown in Table 1. Once the processing of Touquoy stockpiles is completed, in early calendar year 2028, the processing plant is intended to be relocated to the 15-Mile Mine site to support construction of the 15-Mile Processing Hub Project. Production from the 15-Mile Processing Hub Project is anticipated to be sourced solely from the four deposits at 15-Mile Mine until Year Three, at which time mining and ore haulage commences at the Old Mitchell Mine, followed by mining and ore haulage at the Old Austen Mine in Year Four. The mining sequence across the deposits has been optimised to deliver a stable gold production profile over the life of mine while also balancing fleet requirements across the three sites. The 15-Mile Processing Hub Project is anticipated to be funded from cash on hand and anticipated operating cash flows generated from the Touquoy Restart and the New Simberi Gold Project. Table 1. Indicative Timeline of Major Milestones for the Nova Scotia Gold Projects Next Steps St Barbara is currently undertaking an update of the Pre- Feasibility Study (“PFS Update”) for the 15- Mile Processing Hub Project to evaluate the impact of the larger Mineral Resource Estimate ahead of the planned Feasibility Study. The PFS Update is scheduled for release at the end of Q1 September FY27. The Feasibility Study continues to be targeted for completion in Q4 June FY27 to coincide with the anticipated FID date. The recent IPD permit submission to the IAAC has met conformity and has progressed through the public comment period. The next step is for the Company to respond to the IAAC Summary of Issues document, which will inform IAAC’s determination of the applicable permitting process. This determination will take into consideration the recently signed cooperation agreement between Canada and Nova Scotia, which aims to support a “one project, one review” regulatory approach. In parallel, permitting activities continue to advance with technical studies underway to support submission of the Environmental Impact Assessment in Q3 March FY27. The Province of Nova Scotia continues to encourage resource development. The Province has form ed a Mining Roundtable to address regulatory barriers, implement streamlined approval processes, provide for dedicated review
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St Barbara Quarterly Report / Q4 June FY26 Page 4 of 32 teams and to advance major mining projects through approval to development. The roundtable is co-chaired by the Honourable Tory Rushton (Nova Scotia Minister of Natural Resources) and Andrew Strelein (St Barbara Managing Director and CEO). New Simberi Gold Project Construction of the expansion of the New Simberi Gold Project is well underway. Table 2 below shows the indicative timeline with commissioning of the ball mill in Q4 June FY27 and of the flotation plant in Q4 June FY28. Table 2. Indicative Timeline of Major Milestones for the New Simberi Gold Project Crushing and Grinding Circuit The new 5.8 MW ball mill ordered in March 2025 is ready for shipment. The ball mill will depart China in early August and is expected to be delivered to site in early October. Engineering design for the grinding circuit is approximately 50% complete. Flotation circuit and balance of plant design work is underway and approximately 10% complete. Design work on the power station has been completed. The electrical buildings and switchgear for the power station is ordered. New Wharf The contract for the new wharf has been awarded. Construction activity is currently planned for Q1 September FY27. Site Construction Earthworks commenced on construction of the laydown facility and necessary early plant demolition work is underway. The demolition of the pebble crusher is near complete and a roadway to enable access for the piling contractor to commence is well advanced. Procurement (Stages 1 and 2) is 50% complete with 67 of 134 packages approved. Stage 1 is at 63% (33 of 52 awarded). Construction contract packages are out for tender for both concrete work and the structural, mechanical and piping works.
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St Barbara Quarterly Report / Q4 June FY26 Page 5 of 32 Figure 1: Pebble crushing circuit demolition Camp Expansion The new mess has been completed with handover to operations at end of July 2026. The Stage 2 camp expansion is underway, with a new water and sewerage treatment plant being tendered and will be awarded in July. A new construction camp was ordered to provide an additional 284 beds, with earthworks now underway. Civil Construction and Haul Road The contract for civil construction work was awarded to China Harbour Engineering Company (“CHEC”) and onboarding of equipment and personnel is underway. The early earthworks package continues to progress as a critical item prior to arrival of CHEC. Rock material for the waste rock dump underdrains is on site. Reverse Osmosis Water Treatment Plant The Reverse Osmosis (“RO”) Plant is nearing completion, with final piping and electrical work and commissioning underway. Figure 2: RO plant major pipe culvert and electrical work
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St Barbara Quarterly Report / Q4 June FY26 Page 6 of 32 Safety and sustainability St Barbara’s 12-month moving average Total Recordable Injury Frequency Rate (“TRIFR”) for Nova Scotia and Exploration was zero at the end of Q4 June FY26. No reportable medically treatable injuries occurred during the quarter. In Nova Scotia, reclamation is advancing including material movement for the final tailings cover for closure. This project will coincide with the transport of medium and low -grade ore to be hauled to the processing plant for the Touquoy Restart project. The Final Closure and Reclamation Plan document will be submitted to Nova Scotia Department of Natural Resources and Department of Environment and Climate Change on 31 July 2026. New Simberi Gold’s 12-month moving average TRIFR improved to an impressive 0.4 at the end of Q4 June FY26 compared to 0.5 at the end of Q3 March FY26. Rehabilitation activities at New Simberi continued during Q4 June FY26, with a further 0.44 hectares of new rehabilitated area and a year-end total of 5.81 hectares rehabilitated over FY26.
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St Barbara Quarterly Report / Q4 June FY26 Page 7 of 32 Operations New Simberi Gold Project (100% basis)1 Production Summary Q4 Jun FY25 Q1 Sep FY26 Q2 Dec FY26 Q3 Mar FY26 Q4 Jun FY26 Year FY25 Year FY26 Ore Mined kt 614 507 548 679 563 2,410 2,297 Waste mined kt 1,303 1,639 1,941 1,558 1,905 6,320 7,043 Mined grade g/t 1.16 0.94 0.85 0.99 1.11 1.16 0.98 Ore milled kt 533 469 404 494 589 1,919 1,956 Milled grade g/t 1.29 1.03 0.95 1.09 1.00 1.18 1.02 Recovery % 66 72 74 78 77 70 75 Gold production oz 14,620 11,158 9,057 13,522 14,658 51,168 48,395 Gold sold oz 14,711 11,738 10,169 11,974 13,399 48,354 47,280 Realised gold price A$/oz 5,121 5,318 6,404 6,892 6,314 4,428 6,232 All-In Sustaining Cost (AISC) A$/oz produced 4,613 4,487 6,518 4,323 4,514 4,582 4,829 Attributable gold production oz - - - - 7,329 51,168 41,066 Attributable gold sold oz - - - - 6,700 48,354 40,581 Attributable realised gold price A$/oz - - - - 6,314 4,428 6,232 Attributable All-In Sustaining Cost (AISC) A$/oz produced - - - - 4,514 4,582 4,829 1. Operational results are reported at 100%. St Barbara's Q4 June FY26 attributable share for gold production and gold sold was 50%. New Simberi’s production for Q4 June FY26 was 14,658 ounces (100% basis), an 8% improvement compared to Q3 March FY26, with processed tonnes increasing to 589 kt (up 19% on Q3 March FY26) and an average processing feed grade of 1.00 g/t gold. Total mining volumes improved to 2,467 kt (up 10% on Q3 March FY26), with the operation focused on removing the backfill waste material in the Pigibo open pit. Ore mined decreased during this focus on backfill removal to 563 kt (down 17% on Q3 March FY26) but was offset by higher mined grade of 1.11 g/t gold (up 12% on Q3 March FY26). St Barbara’s attributable gold production from New Simberi for Q4 June FY26 was 7,329 ounces (i.e. 50% of 14,658 total ounces) coming in ahead of updated guidance of 5,600 to 6,800 ounces (i.e. 40% of 14,000 to 17,000 ounces) 3. Attributable gold sales for Q4 June FY26 were 6,700 ounces sold at an average gold price of A$6,314 per ounce. St Barbara’s attributable production from New Simberi is expected to move to 40% (from the 50% reported for Q4) from July 2026 onwards following anticipated completion of the remaining condition precedent for completion of the transaction with Kumul to acquire 20% of the New Simberi Gold Project from St Barbara and Lingbao. 3 Refer to ASX announcement dated 29 April 2026 titled “Quarterly Report Q3 March FY26”
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St Barbara Quarterly Report / Q4 June FY26 Page 8 of 32 Exploration activities Papua New Guinea New Simberi Resource Definition and Sterilisation Drilling A total of 10 diamond drill holes ( holes SDH726 to SDH735) were completed at New Simberi in PNG during Q4 June FY26, totalling 1,411.1 metres, as part of the FY26 resource definition, exploration and sterilisation drill program. This included seven Samat exploration drill holes for 931.6 metres, two Pigiput Northeast resource definition drill holes for 347.3 metres, and one Andora exploration drill hole for 132.2 metres. The FY26 resource definition, exploration and sterilisation drill program completed at the New Simberi Operations comprised 45 drill holes (SDH683 to SDH693, SDH695, SDH697, SDH699, SDH701 to SDH705, SDH709, SDH711 to SDH735), totalling 6,325.6 metres. This included 12 Darum waste rock dump sterilisation/exploration drill holes for 1,529.5 metres, 19 Samat exploration drill holes for 2, 442.1 metres, four Pigiput Northeast Trend resource definition drill holes for 994.5 metres, four Pigibo West resource definition drill holes for 437.3 m etres, three Pigiput Southwest resource definition drill holes for 535.8 metres, and three Northeast Andora exploration drill holes for 386.4 metres. Assay results were received for eight diamond drill holes in Q4 June FY26, including the remaining four of eight holes drilled in Q3 March FY26 and four of eight holes drilled in Q4 June FY26. Updated assay results from ALS were also received for eight holes previously reported using the New Simberi site laboratory. At Pigiput Southwest, best results include: • SDH721: 23 m @ 4.2 g/t Au from 110 m, including 4 m @ 20.9 g/t Au from 127 m; and • SDH722: 21.3 m @ 1.8 g/t Au from 160 m. The gold mineralisation in SDH721 is associated with a zone of moderately to strongly oxidised, silica- clay altered, brecciated andesite with 3 to 10% sulphides. The intercept is located 100 m vertically below the southeast limit to the current Pigiput sulphide Ore Reserve pit design. The nearest drilling is located 90 m to the north. The gold mineralisation in SDH722 is associated with a zone of fresh, sericite-silica-clay altered polymict breccia and andesite with carbonate- quartz filled fractures and vugs and 3 to 10% disseminated sulphides. The intercept is located 20 m to 33 m vertically below the current Pigiput sulphide Ore Reserve pit design. At Samat, best results include: • SDH725: 7 m @ 5.8 g/t Au from 86 m; • SDH727: 4 m @ 6.4 g/t Au from 47 m; and • SDH728: 44 m @ 1.4 g/t Au from 14 m and 4 m @ 6.5 g/t Au from 64 m. The gold mineralisation is associated with fresh sericite-silica-clay altered polymict breccia, monomict andesite breccia, and andesite with 5 to 12 % sulphides. The SDH728 intercept is located within the current Samat sulphide Ore Reserve pit design. The SDH725 intercept is located between 15 m and 20 m vertically below the current Samat sulphide Ore Reserve pit design. The second SDH728 intercept from 64 m is located between 0 m and 5 m below the current Samat sulphide Ore Reserve pit design. At Pigiput Northeast, best results include: • SDH729: 32 m @ 1.1 g/t Au from 33 m. The gold mineralisation is associated with oxidised, strong limonite fractured, sericite-clay altered, polymict breccia and andesite, located within the current Pigiput sulphide Ore Reserve pit design. 43 trenches ( trenches SIMTR1073 to SIMTR 1115), totalling 3,415 metres, were completed in FY26 along ML136 access tracks around Darum waste rock dump, the Pigiput , Samat and Andora deposits, as well as the proposed new haul road. Final results were received for 10 trenches (trenches SIMTR1100 to SIMTR1109). At Samat, best results include: • SIMTR1108: 15 m @ 2.9 g/t Au including 5 m @ 4.7 g/t Au, 25 m @ 0.9 g/t Au; and • SIMTR1109: 20 m @ 3.5 g/t Au including 10 m @ 5.2 g/t Au, 15 m @ 2.2 g/t Au .
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St Barbara Quarterly Report / Q4 June FY26 Page 9 of 32 Both trenches intersected oxide mineralisation associated with strong alteration. SIMTR1109 is located within the current Samat sulphide Ore Reserve pit design, whereas SIMTR1108 is located between 30 m to 100 m southeast of the Samat sulphide Ore Reserve pit design. Papua New Guinea Tatau & Tabar Islands A regional hand-auger soil sampling program comprising 130 samples was completed between January and May 2026. Samples were collected on a staggered 200 m x 200 m grid covering part of northern Tatau Island within EL609. An additional 138 rock chips samples were collected during the soil sampling program. A program of up to 10 Reverse Circulation (RC) drill holes for 600 m is planned to test copper-gold surface geochemical anomalies on eastern Tatau Island during Q1 FY27. Canada St Barbara’s current Atlantic tenement holding comprises one mining lease (MLE 11- 1) and 171 exploration licences totalling 4,213 claims covering 68,208 hectares. A regional surface sampling program designed to test 18 priority areas is underway. The program, comprising up to 2,075 till and rock chip samples, commenced in May 2026 and is expected to be completed in September 2026. A total of 971 surface samples (comprising 768 till samples and 203 rock chip samples) were collected during Q4 June FY26, representing 47% of the planned program. Samples were collected from the following six areas : Ferry Lake / Mooseland North, West Caledonia, Gold Lake, Oldham, Touquoy South and Harrigan Cove. A 1,069.7 line-kilometre UAV magnetic survey was completed at West Caledonia in June 2026. A combined RC and Interface Reverse Circulation drill program, comprising up to 96 drill holes for 3,250 metres has been designed to test between four and six targets. The drilling is expected to commence in August 2026 subject to drill contractor timing and weather conditions. Australia Back Creek, New South Wales A combined 1,641 line-kilometre UAV magnetic survey is scheduled for H1 FY27, covering the Southwest Target (1,135 line-kilometres) and Northeast Target (506 line-kilometres). The survey will provide additional information to support further drill targeting beneath cover in H2 FY27.
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St Barbara Quarterly Report / Q4 June FY26 Page 10 of 32 Figure 3. Q4 June FY26 Completed Trenching and Diamond Drilling, Simberi Island
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St Barbara Quarterly Report / Q4 June FY26 Page 11 of 32 Figure 4. Q4 June FY26 Completed Trenching and Diamond Drilling Pigiput, Simberi Island
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St Barbara Quarterly Report / Q4 June FY26 Page 12 of 32 Figure 5. Q4 June FY26 Completed Trenching and Diamond Drilling, Samat, Simberi Island, Papua New Guinea
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St Barbara Quarterly Report / Q4 June FY26 Page 13 of 32 Figure 6. Q4 June FY26 Completed Trenching and Diamond Drilling, Darum Waste Rock Dump, Simberi Island, Papua New Guinea
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St Barbara Quarterly Report / Q4 June FY26 Page 14 of 32 Figure 7. Q4 June FY26 Completed Work Programs, 15-Mile Hub, Nova Scotia Figure 8. Q4 June FY26 Completed Regional Work Programs, Nova Scotia
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St Barbara Quarterly Report / Q4 June FY26 Page 15 of 32 Finance (unaudited) St Barbara’s attributable gold sales were 6,700 ounces from New Simberi in Q4 June FY26 (i.e. 50% of 13,399 ounces) at an average realised price of A$6,314 per ounce. A further 187 ounces of gold were sold at an average realised price of A$6,572 per ounce from gold recovery work at the Touquoy processing plant. The Company continues to have no debt and no hedging. As at 30 June 2026 St Barbara’s cash balance was A$475 million. Attributable cash and gold bullion at New Simberi Gold Group was a further A$21 million. Listed investments were another A$13 million. Growth capital expenditure for the Nova Scotia Projects in Q4 June FY26 was A$4 million. Exploration expenditure in Q4 June FY26 for Nova Scotia and Back Creek was A$1 million. Touquoy rehabilitation expenditure was A$1 million in Q4 June FY26, while care and maintenance expenditure was A$3 million. New Simberi operational cash flow contribution for Q4 June FY26 (100% basis) was A$29 million, growth capital expenditure was A$22 million, sustaining capital expenditure was A$1 million and exploration expenditure was A$1 million. Cash, Gold and Investment Balance (A$M) – Q4 June FY26 St Barbara Ltd New Simberi Gold Group (50% Attributable) Total (inc. attributable) Cash 475* 18 493* Gold bullion in Safe - 3 3 Sub-Total 475 21 496 Listed Investments 13 - 13 Total 488 21 509 * Includes A$82M restricted cash
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St Barbara Quarterly Report / Q4 June FY26 Page 16 of 32 Historic Quarter-on-Quarter Detailed Cash & Other Movement (A$M) St Barbara Limited Cash movements & balance A$M Q4 Jun Q1 Sep Q2 Dec Q3 Mar Q4 Jun Year (unaudited) FY25 FY26 FY26 FY26 FY26 FY26 New Simberi Growth Projects (13) (16) (19) (25) - (60) Operations 8 9 14 13 - (37) Sustaining Capex (1) - (1) (1) - (2) Atlantic Growth Projects (2) (2) (3) (2) (4) (11) Operations 4 - - 2 1 3 Care & Maintenance (4) (2) (2) (3) (3) (10) Rehabilitation (4) (1) (1) (1) (1) (4) Exploration (1) (2) (3) (2) (1) (8) Corporate Costs (3) (3) (3) (2) (3) (11) Working Cap. / Other Balance Sheet Items 16 (18) (10) (20) (10) (59) Cashflows before financing costs - (35) (28) (41) (21) (125) New Simberi Gold Financing - - - - (13) (13) Net Interest income/(expense) 2 2 - - 3 5 Other Financing and Assets sales - 10 58 - 389 457 Transaction costs - - (2) - (4) (6) Net Movement for Period 2 (23) 28 (41) 354 318 Cash Balance at start of quarter 155 157 134 162 121 157 Total Cash at end of quarter 157 134 162 121 475 475 Cash available for use 68 47 75 38 393 393 Restricted cash 89 87 87 83 82 82 Gold in Safe 4 2 8 5 - - Gold Sales Receivable - 3 - 21 - - Total Cash & Gold at end of quarter 161 139 170 147 475 475 New Simberi Gold Group (Investment in Associate at 100%) Cash movements & balance A$M Q4 Jun Q1 Sep Q2 Dec Q3 Mar Q4 Jun Year (unaudited) FY25 FY26 FY26 FY26 FY26 FY26 Growth Capex - - - - (22) (22) Operations 29 29 Sustaining Capex - - - - (1) (1) Exploration - - - - (1) (1) Corporate Costs - - - - (2) (2) Working Cap. / Other Balance Sheet Items - - - - 13 13 Cashflows before financing costs - - - - 16 16 Financing from Shareholders - - - - 15 15 Net Movement for Period - - - - 31 31 Cash Balance at start of quarter - - - - 6 6 Total Cash at end of quarter - - - - 37 37 Cash available for use - - - - 37 37 Gold in Safe - - - - 5 5 Gold Sales Receivable - - - - - - Total Cash & Gold at end of quarter - - - - 42 42
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St Barbara Quarterly Report / Q4 June FY26 Page 17 of 32 St Barbara Limited and Attributable Share of New Simberi Gold Group Cash A$M Q4 Jun Q1 Sep Q2 Dec Q3 Mar Q4 Jun Year (unaudited) FY25 FY26 FY26 FY26 FY26 FY26 Attributable Total Cash - - - - 493 493 Attributable Gold in Safe - - - - 3 3 Total Attributable Cash & Gold - - - - 496 496 Equity Investments St Barbara’s listed investment portfolio consisted of the equity position in Geopacific Resources Limited (“Geopacific”) shown below. The value of the Geopacific shareholding decreased from A$23 million at the end of March 2026 to A$13 million at 30 June 2026. Company Shares (M) Ownership (%) Value (A$M) Geopacific Resources Limited (ASX: GPR) 458.6 14.3 12.8* *Based on closing share price on 30 June 2026 Authorised by Andrew Strelein Managing Director & CEO 30 July 2026 For more information Investor Relations Media Relations David Cotterell General Manager Business Development & Investor Relations info@stbarbara.com.au T: +61 3 8660 1959 M: +61 447 644 648 Paul Ryan Sodali & Co M: +61 409 296 511 St Barbara Limited ACN 009 165 066 Level 19, 58 Mounts Bay Road, Perth WA 6000 ASX: SBM PO Box 1161, West Perth WA 6872 T +61 8 9476 5555 F +61 8 9476 5500 stbarbara.com.au
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St Barbara Quarterly Report / Q4 June FY26 Page 18 of 32 Share capital Issued shares ASX:SBM Opening Balance 31 March 2026 1,209,795,861 Issued Nil Closing balance 30 June 2026 1,209,795,861 Unlisted employee rights ASX:SBMAK Opening balance 31 March 2026 88,671,113 Issued Nil Exercised as shares Nil Lapsed4 675,652 Closing balance 30 June 2026 87,995,461 Comprises rights expiring: 30 June 2026 45,858,658 30 June 2027 24,459,077 30 June 2028 17,677,726 Unlisted rights issued under the NED Equity Plan Nil Closing balance 30 June 2026 87,995,461 4 Rights lapsed due to conditions not being met.
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St Barbara Quarterly Report / Q4 June FY26 Page 19 of 32 Corporate directory St Barbara Limited ABN 36 009 165 066 Board of Directors Kerry Gleeson, Non-Executive Chair Andrew Strelein, Managing Director & CEO Mark Hine, Non-Executive Director Warren Hallam, Non-Executive Director Company Secretary Kylie Panckhurst, General Counsel & Company Secretary Executives Andrew Strelein, Managing Director & CEO Sara Prendergast, Chief Financial Officer Craig Hudson, EVP Atlantic Brett Ascott, EGM Projects & Technical Support Roger Mustard, EGM Exploration Registered Office Level 19, 58 Mounts Bay Road Perth Western Australia 6000 Australia T +61 8 9476 5555 F +61 8 9476 5500 E info@stbarbara.com.au stbarbara.com.au Australian Securities Exchange (ASX) Listing code “SBM” Financial figures are in Australian dollars (unless otherwise noted) Financial year commences 1 July and ends 30 June Q1 September FY26 = quarter to 30 September 2025 Q2 December FY26 = quarter to 31 December 2025 Q3 March FY26 = quarter to 31 March 2026 Q4 June FY26 = quarter to 30 June 2026 5 As notified by the substantial shareholder up to 29 July 2026. Shareholder Enquiries Computershare Investor Services Pty Ltd GPO Box 2975 Melbourne Victoria 3001 Australia T 1300 653 935 (within Australia) T +61 3 9415 4356 (international) F +61 3 9473 2500 www.investorcentre.com/au Investor Relations David Cotterell, General Manager Business Development & Investor Relations T +61 3 8660 1959 M +61 447 644 648 Substantial Shareholders % of Holdings5 Paradice Investment Management Pty Ltd 6.9% Vanguard Group 5.7% Baker Steel Capital Managers LLP 5.2%
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St Barbara Quarterly Report / Q4 June FY26 Page 20 of 32 Production and All-In Sustaining Cost6 Production summary New Simberi Operations Q1 Sep FY25 Q2 Dec FY26 Q3 Mar FY26 Q4 Jun FY26 Year FY26 Ore Mined kt 507 548 679 563 2,297 Waste mined / in-pit handling kt 1,639 1,941 1,558 1,905 7,043 Mined grade g/t 0.94 0.85 0.99 1.11 0.98 Ore milled kt 469 404 494 589 1,956 Milled grade g/t 1.03 0.95 1.09 1.00 1.02 Recovery % 72 74 78 77 75 Gold production oz 11,158 9,057 13,522 14,658 48,395 Gold sold oz 11,738 10,169 11,974 13,399 47,280 Realised gold price A$/oz 5,318 6,404 6,892 6,314 6,232 All-In Sustaining Cost7 A$/oz produced Mining 2,299 2,803 1,785 1,674 2,060 Processing 1,633 2,081 1,257 1,418 1,547 Site Services 1,269 1,534 974 966 1,144 Stripping and ore inventory adj (1,006) (381) (25) 173 (258) 4,195 6,037 3,991 4,231 4,493 By-product credits (45) (51) (33) (22) (36) Third party refining & transport 38 50 17 14 27 Royalties 135 179 155 144 151 Total cash operating costs 4,323 6,215 4,130 4,367 4,635 Corporate and administration 55 54 22 22 36 Rehabilitation 85 165 108 66 101 Sustaining capital expenditure 24 84 63 59 57 All-In Sustaining Cost (AISC) 4,487 6,518 4,323 4,514 4,829 Attributable gold production oz - - - 7,329 41,066 Attributable gold sold oz - - - 6,700 40,581 Attributable realised gold price A$/oz - - - 6,314 6,232 Attributable All-In Sustaining Cost (AISC) A$/oz - - - 4,514 4,829 6 All New Simberi operating metrics are reported on a 100% basis with St Barbara's Q4 June FY26 attributable share for gold production and gold sold at 50%. 7 Non-IFRS measure, refer Page 21
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St Barbara Quarterly Report / Q4 June FY26 Page 21 of 32 Disclaimer This report has been prepared by St Barbara Limited (“Company”). The material contained in this report is for information purposes only. This release is not an offer or invitation for subscription or purchase of, or a recommendation in relation to, securities in the Company and neither this release nor anything contained in it shall form the basis of any contract or commitment. This report contains forward-looking statements that are subject to risk factors associated with exploring for, developing, mining, processing and the sale of gold. Forward-looking statements include those containing such words as anticipate, estimates, forecasts, indicative, should, will, would, expects, plans or similar expressions. Such forward-looking statements are not guarantees of future performance and involve known and unknown risks, uncertainties, assumptions and other important factors, many of which are beyond the control of the Company, and which could cause actual results or trends to differ materially from those expressed in this report. Actual results may vary from the information in this report. The Company does not make, and this report should not be relied upon as, any representation or warranty as to the accuracy, or reasonableness, of such statements or assumptions. Investors are cautioned not to place undue reliance on such statements. This report has been prepared by the Company based on information available to it, including information from third parties, and has not been independently verified. No representation or warranty, express or implied, is made as to the fairness, accuracy or completeness of the information or opinions contained in this report. To the maximum extent permitted by law, neither the Company, their directors, employees or agents, advisers, nor any other person accepts any liability, including, without limitation, any liability arising from fault or negligence on the part of any of them or any other person, for any loss arising from the use of this presentation or its contents or otherwise arising in connection with it. Non-IFRS measures The Company supplements its financial information reporting determined under International Financial Reporting Standards (IFRS) with certain non-IFRS financial measures, including Cash Operating Costs and All-In Sustaining Cost. We believe that these measures provide additional meaningful information to assist management, investors and analysts in understanding the financial results and assessing our prospects for future performance. All-In Sustaining Cost (AISC) is based on Cash Operating Costs and adds items relevant to sustaining production. It includes some, but not all, of the components identified in World Gold Council’s Guidance Note on Non-GAAP Metrics - All-In Sustaining Costs and All-In Costs (June 2013). • AISC is calculated on gold production in the quarter. • For underground mines, amortisation of operating development is adjusted from “Total Cash Operating Costs” in order to avoid duplication with cash expended on operating development in the period contained within the “Mine & Operating Development” line item. • Rehabilitation is calculated as the amortisation of the rehabilitation provision on a straight-line basis over the estimated life of mine. Cash Contribution is cash flow from operations before finance costs, refer reconciliation of cash movement earlier in this quarterly report. Cash Operating Costs are calculated according to common mining industry practice using The Gold Institute (USA) Production Cost Standard (1999 revision). Competent Persons Statement Exploration results The information in this report that relates to Exploration Results is based on information compiled by Dr Roger Mustard, who is a Member of The Australasian Institute of Mining and Metallurgy. Dr Mustard is a full-time employee of St Barbara and has sufficient experience relevant to the style of mineralisation and type of deposit under consideration and to the activity which he is undertaking to qualify as a Competent Person as defined in the 2012 Edition of the ‘Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves’. Dr Mustard consents to the inclusion in the report of the matters based on his information in the form and context in which it appears.
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St Barbara Quarterly Report / Q4 June FY26 Page 22 of 32 Table 1: New Simberi Diamond Drilling Significant Intercepts – Simberi Island, Papua New Guinea. Hole No TIG North TIG East RL Dip/ Azimuth Total Depth Oxidation Down-hole Mineralised Intersection From m To m Length m Gold Grade (Au g/t) SDH712 209,231 44,440 160.7 -59 / 315 229.3 SU 83.0 86.0 3.0 0.9 SU 94.0 114.0 20.0 1.1 including SU 108.0 111.0 3.0 2.8 SU 168.0 170.0 2.0 1.3 SDH715 208,200 44,189 125.7 -61 / 115 143.5 TR,SU 39.0 47.0 8.0 2.0 including SU 41.0 42.0 1.0 7.9 SDH716 208,390 44,246 150.7 -60 / 114 158.5 No significant Results SDH717 208,018 44,568 89.0 -60 / 314 86.5 No significant Results SDH718 207,993 44,648 95.7 -60 / 138 160.1 SU 9.0 24.0 15.0 1.6 including SU 13.0 17.0 4.0 3.1 SU 56.0 60.0 4.0 0.8 SU 81.0 86.0 5.0 0.7 SDH719 207,996 44,724 83.6 -60 / 137 131.8 No significant Results SDH720 207,966 44,793 86.1 -60 / 141 101.3 No significant Results SDH721 208,725 44,363 211.2 -58 / 128 194.5 TR 54.0 55.0 1.0 2.6 OX,TR 110.0 133.0 23.0 4.2 TR 127.0 131.0 4.0 20.9 SDH722* 209,082 44,190 175.0 -61 / 137 181.3 TR,SU 41.0 49.0 8.0 1.7 including TR 42.0 43.0 1.0 6.3 and SU 47.0 48.0 1.0 2.8 SU 79.0 142.0 63.0 1.0 including SU 89.0 90.0 1.0 2.9 and SU 101.0 102.0 1.0 3.4 SU 160.0 181.3 21.3 1.8 including SU 166.0 167.0 1.0 3.8 and SU 178.0 179.0 1.0 14.1 SDH723* 209,030 44,149 218.2 -60 / 138 160.0 SU 75.0 77.0 2.0 1.4 TR 117.0 120.0 3.0 2.3 including TR 117.0 118.0 1.0 5.6 SDH724* 208,633 44,161 133.1 -60 / 136 115.0 OX,TR 6.0 19.0 13.0 1.2 including TR 17.0 18.0 1.0 2.8 SDH725 207,357 44,660 60.7 -61 / 217 98.6 SU 29.0 43.0 14.0 0.8 including SU 41.0 43.0 2.0 2.3 SU 86.0 93.0 7.0 5.8 including SU 87.0 91.0 4.0 9.3 including SU 88.0 89.0 1.0 25.2 SDH726 207,324 44,723 56.9 -60 / 220 140.7 SU 26.0 34.0 8.0 2.2 SU 87.0 99.0 12.0 1.3 including SU 96.0 98.0 2.0 4.0 SU 129.0 136.0 7.0 0.8 including SU 130.0 131.0 1.0 3.0 SDH727 207,387 44,605 60.7 -60 / 223 114.5 SU 47.0 51.0 4.0 6.4 including 47.0 49.0 2.0 8.8 SU 74.0 79.0 5.0 1.1 including SU 74.0 75.0 1.0 2.6 NOTES: *: Site Lab Results OX: oxide, SU: sulphide, TR: transitional material
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St Barbara Quarterly Report / Q4 June FY26 Page 23 of 32 Table 1 Cont: New Simberi Diamond Drilling Significant Intercepts – Simberi Island, Papua New Guinea. Hole No TIG North TIG East RL Dip/ Azimuth Total Depth Oxidation Down-hole Mineralised Intersection From m To m Length m Gold Grade (Au g/t) SDH728* 207,440 44,547 78.9 -66 / 217 145.7 TR,SU 14 58 44 1.4 including SU 21 26 5 2.9 and SU 46 48 2 2.8 and SU 54 55 1 2.6 SU 64 68 4 6.5 including SU 65 67 2 12.3 including SU 66 67 1 21.0 SDH729* 209,205 44,706 220.8 -58 / 111 167.7 OX,TR 33 65 32 1.1 including TR 62 63 1 2.7 and TR 64 65 1 3.9 TR,SU 112 125 13 1.5 including TR,SU 121 124 3 4.0 including TR,SU 123 124 1 5.6 NOTES: *: Site Lab Results OX: oxide, SU: sulphide, TR: transitional material Table 2: New Simberi Trench Significant Intercepts – Simberi Island, Papua New Guinea. Trench No Sample Length m Number Of Samples Trench Length m Start North m Start East m Start RL m End North m End East m End RL m From m To m Interval m Gold Grade Au g/t SIMTR1100* 5 6 30 209,057 44,124 213 209,045 44,149 218 No Significant Results SIMTR1101* 5 8 40 209,021 44,144 220 208,988 44,164 218 No Significant Results SIMTR1102* 5 7 35 208,633 44,161 133 208,615 44,135 124 15 35 20.0 1.1 SIMTR1103* 5 4 20 208,555 44,098 126 208,561 44,116 121 No Significant Results SIMTR1104* 5 18 90 208,554 44,121 127 208,487 44,152 125 0 5 5.0 0.6 SIMTR1105* 5 32 160 208,445 44,245 121 208,363 44,124 142 65 70 5.0 0.7 SIMTR1106* 5 56 280 207,278 44,446 95 207,190 44,596 106 No Significant Results SIMTR1107* 5 19 95 207,145 44,639 101 207,159 44,717 107 No Significant Results SIMTR1108* 5 22 110 207,174 44,719 101 207,165 44,824 77 10 25 15.0 2.9 including 10 15 5.0 4.7 60 85 25.0 0.9 including 60 65 5.0 1.3 and 80 85 5.0 1.5 SIMTR1109* 5 14 70 207,290 44,636 59 207,264 44,682 57 0 20 20.0 3.5 including 10 20 10.0 5.2 30 35 5.0 0.6 including 55 70 15.0 2.2 and 55 60 5.0 3.3 NOTES: * Site Lab Results
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St Barbara Quarterly Report / Q4 June FY26 Page 24 of 32 Table 3: New Simberi Trench Assay Results – Simberi Island, Papua New Guinea. Sample Type Trench No From m To m Interval m North m East m RL m Lith Code Gold Grade Au g/t Collar SIMTR1100* 0 N/A 209,057 44,124 213.0 Trench SIMTR1100* 0 5 5 209,057 44,129 215.2 Moderate Argillic Matrix-dominated Breccia 0.01 Trench SIMTR1100* 5 10 5 209,055 44,134 216.4 Moderate Argillic Matrix-dominated Breccia 0.02 Trench SIMTR1100* 10 15 5 209,053 44,138 218.3 Moderate Argillic Matrix-dominated Breccia 0.02 Trench SIMTR1100* 15 20 5 209,049 44,141 219.3 Moderate Argillic Matrix-dominated Breccia 0.02 Trench SIMTR1100* 20 25 5 209,045 44,144 218.7 Moderate Argillic Matrix-dominated Breccia 0.01 Trench SIMTR1100* 25 30 5 209,045 44,149 217.6 Moderate Argillic Matrix-dominated Breccia 0.01 Collar SIMTR1101* 0 N/A 209,021 44,144 219.6 Trench SIMTR1101* 0 5 5 209,016 44,146 219.2 Sandstone 0.05 Trench SIMTR1101* 5 10 5 209,012 44,148 218.6 Moderate Argillic Matrix-dominated Breccia 0.02 Trench SIMTR1101* 10 15 5 209,009 44,152 217.5 Moderate Argillic Matrix-dominated Breccia 0.03 Trench SIMTR1101* 15 20 5 209,007 44,156 216.5 Strong Argillic Matrix-dominated Breccia 0.02 Trench SIMTR1101* 20 25 5 209,002 44,159 216.4 Strong Argillic Matrix-dominated Breccia 0.02 Trench SIMTR1101* 25 30 5 208,998 44,161 216.9 Strong Argillic Matrix-dominated Breccia 0.01 Trench SIMTR1101* 30 35 5 208,993 44,163 217.6 Strong Argillic Matrix-dominated Breccia 0.02 Trench SIMTR1101* 35 40 5 208,988 44,164 218.3 Moderate Argillic Matrix-dominated Breccia 0.01 Collar SIMTR1102* 0 N/A 208,633 44,161 133.0 Trench SIMTR1102* 0 5 5 208,633 44,156 131.3 Strong Argillic Polymict Breccia 0.48 Trench SIMTR1102* 5 10 5 208,630 44,152 129.0 Strong Argillic Polymict Breccia 0.01 Trench SIMTR1102* 10 15 5 208,626 44,149 127.3 Strong Argillic Polymict Breccia 0.01 Trench SIMTR1102* 15 20 5 208,622 44,146 125.2 Strong Argillic Polymict Breccia 0.67 Trench SIMTR1102* 20 25 5 208,618 44,144 125.1 Weak Argillic Polymict Breccia 0.02 Trench SIMTR1102* 25 30 5 208,616 44,139 124.7 Moderate Argillic Monomict Andesite Breccia 2.19 Trench SIMTR1102* 30 35 5 208,615 44,135 124.3 Moderate Argillic Monomict Andesite Breccia 1.33 Collar SIMTR1103* 0 0 N/A 208,555 44,098 126.1 Trench SIMTR1103* 0 5 5 208,556 44,103 123.6 Weak Argillic Andesite Intrusive 0.01 Trench SIMTR1103* 5 10 5 208,556 44,108 124.0 Weak Argillic Andesite Intrusive 0.02 Trench SIMTR1103* 10 15 5 208,559 44,112 122.2 Moderate Argillic Andesite Intrusive 0.01 Trench SIMTR1103* 15 20 5 208,561 44,116 121.4 Moderate Argillic Andesite Intrusive 0.08 Collar SIMTR1104* 0 N/A 208,554 44,121 127.1 Trench SIMTR1104* 0 5 5 208,552 44,125 130.6 Weak Argillic Andesite Intrusive 0.62 Trench SIMTR1104* 5 10 5 208,547 44,128 130.8 Weak Argillic Andesite Intrusive 0.02 Trench SIMTR1104* 10 15 5 208,543 44,130 131.5 Weak Argillic Andesite Intrusive 0.01 Trench SIMTR1104* 15 20 5 208,538 44,132 131.9 Strong Argillic Monomict Andesite Breccia 0.03 Trench SIMTR1104* 20 25 5 208,534 44,135 130.9 Strong Argillic Monomict Andesite Breccia 0.04 Trench SIMTR1104* 25 30 5 208,530 44,137 132.3 Strong Argillic Monomict Andesite Breccia 0.03 Trench SIMTR1104* 30 35 5 208,525 44,139 133.2 Weak Argillic Andesite Intrusive 0.06 Trench SIMTR1104* 35 40 5 208,522 44,143 133.0 Weak Argillic Andesite Intrusive 0.07 Trench SIMTR1104* 40 45 5 208,520 44,148 131.4 Weak Argillic Andesite Intrusive 0.06 Trench SIMTR1104* 45 50 5 208,517 44,152 131.0 Weak Argillic Andesite Intrusive 0.08 Trench SIMTR1104* 50 55 5 208,515 44,156 129.5 Weak Argillic Andesite Intrusive 0.09 Trench SIMTR1104* 55 60 5 208,511 44,159 128.7 Weak Argillic Andesite Intrusive 0.07 Trench SIMTR1104* 60 65 5 208,507 44,163 127.3 Weak Argillic Polymict Breccia 0.1 Trench SIMTR1104* 65 70 5 208,502 44,164 126.8 Weak Argillic Polymict Breccia 0.1 Trench SIMTR1104* 70 75 5 208,498 44,163 125.6 Weak Argillic Polymict Breccia 0.09 Trench SIMTR1104* 75 80 5 208,494 44,159 125.0 Weak Argillic Polymict Breccia 0.09 Trench SIMTR1104* 80 85 5 208,490 44,156 124.6 Weak Argillic Polymict Breccia 0.11 Trench SIMTR1104* 85 90 5 208,487 44,152 125.3 Weak Argillic Polymict Breccia 0.09 Collar SIMTR1105* 0 N/A 208,445 44,245 121.4 Trench SIMTR1105* 0 5 5 208,442 44,241 121.6 Weak Argillic Andesite Intrusive 0.03 Trench SIMTR1105* 5 10 5 208,438 44,238 125.2 Weak Argillic Andesite Intrusive 0.05 Trench SIMTR1105* 10 15 5 208,435 44,234 125.8 Weak Argillic Andesite Intrusive 0.05 Trench SIMTR1105* 15 20 5 208,431 44,231 123.8 Weak Argillic Polymict Breccia 0.06 Trench SIMTR1105* 20 25 5 208,428 44,228 127.1 Weak Argillic Polymict Breccia 0.07 NOTES: * Site Lab Results Co-ordinates are interval end points
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St Barbara Quarterly Report / Q4 June FY26 Page 25 of 32 Table 3 Cont: New Simberi Trench Assay Results – Simberi Island, Papua New Guinea. Sample Type Trench No From m To m Interval m North m East m RL m Lith Code Gold Grade Au g/t Trench SIMTR1105* 25 30 5 208,424 44,225 125.8 Weak Argillic Polymict Breccia 0.09 Trench SIMTR1105* 30 35 5 208,419 44,223 127.8 Weak Argillic Polymict Breccia 0.09 Trench SIMTR1105* 35 40 5 208,415 44,221 129.7 Weak Argillic Polymict Breccia 0.06 Trench SIMTR1105* 40 45 5 208,411 44,218 129.7 Weak Argillic Polymict Breccia 0.08 Trench SIMTR1105* 45 50 5 208,408 44,214 127.4 Weak Argillic Andesite Intrusive 0.01 Trench SIMTR1105* 50 55 5 208,404 44,211 125.3 Weak Argillic Andesite Intrusive 0.01 Trench SIMTR1105* 55 60 5 208,401 44,207 126.3 Weak Argillic Andesite Intrusive 0.01 Trench SIMTR1105* 60 65 5 208,397 44,204 126.9 Moderate Argillic Polymict Breccia 0.27 Trench SIMTR1105* 65 70 5 208,395 44,199 127.5 Moderate Argillic Polymict Breccia 0.68 Trench SIMTR1105* 70 75 5 208,392 44,195 128.8 Moderate Argillic Polymict Breccia 0.26 Trench SIMTR1105* 75 80 5 208,390 44,191 128.7 Moderate Argillic Polymict Breccia 0.06 Trench SIMTR1105* 80 85 5 208,388 44,186 128.6 Weak Argillic Matrix-dominated Breccia 0.09 Trench SIMTR1105* 85 90 5 208,387 44,181 127.8 Weak Argillic Matrix-dominated Breccia 0.01 Trench SIMTR1105* 90 95 5 208,384 44,177 128.4 Weak Argillic Matrix-dominated Breccia 0.02 Trench SIMTR1105* 95 100 5 208,382 44,173 127.5 Weak Argillic Matrix-dominated Breccia 0.03 Trench SIMTR1105* 100 105 5 208,379 44,169 131.7 Weak Argillic Polymict Breccia 0.02 Trench SIMTR1105* 105 110 5 208,376 44,165 132.6 Weak Argillic Polymict Breccia 0.01 Trench SIMTR1105* 110 115 5 208,375 44,160 133.6 Unaltered/fresh Polymict Breccia 0.01 Trench SIMTR1105* 115 120 5 208,374 44,156 132.8 Unaltered/fresh Polymict Breccia 0.03 Trench SIMTR1105* 120 125 5 208,371 44,152 134.6 Unaltered/fresh Polymict Breccia 0.01 Trench SIMTR1105* 125 130 5 208,368 44,148 134.2 Unaltered/fresh Polymict Breccia 0.01 Trench SIMTR1105* 130 135 5 208,365 44,145 136.6 Unaltered/fresh Polymict Breccia 0.01 Trench SIMTR1105* 135 140 5 208,363 44,141 139.6 Unaltered/fresh Matrix-dominated Breccia 0.01 Trench SIMTR1105* 140 145 5 208,361 44,136 139.3 Unaltered/fresh Matrix-dominated Breccia 0.01 Trench SIMTR1105* 145 150 5 208,358 44,132 140.1 Unaltered/fresh Matrix-dominated Breccia 0.02 Trench SIMTR1105* 150 155 5 208,361 44,128 139.8 Unaltered/fresh Matrix-dominated Breccia 0.03 Trench SIMTR1105* 155 160 5 208,363 44,124 141.7 Unaltered/fresh Matrix-dominated Breccia 0.04 Collar SIMTR1106* 0 N/A 207,278 44,446 95.0 Trench SIMTR1106* 0 5 5 207,276 44,450 96.3 Strong Argillic Monomict Andesite Breccia 0.08 Trench SIMTR1106* 5 10 5 207,272 44,454 98.2 Oxidised clay (limonite/heamatite clay) 0.06 Trench SIMTR1106* 10 15 5 207,267 44,456 99.4 Oxidised clay (limonite/heamatite clay) 0.05 Trench SIMTR1106* 15 20 5 207,263 44,457 100.9 Oxidised clay (limonite/heamatite clay) 0.02 Trench SIMTR1106* 20 25 5 207,258 44,456 102.2 Oxidised clay (limonite/heamatite clay) 0.06 Trench SIMTR1106* 25 30 5 207,254 44,453 103.7 Strong Argillic Andesite Intrusive 0.01 Trench SIMTR1106* 30 35 5 207,249 44,451 105.7 Strong Argillic Andesite Intrusive 0.01 Trench SIMTR1106* 35 40 5 207,245 44,448 107.2 Strong Argillic Monomict Andesite Breccia 0.02 Trench SIMTR1106* 40 45 5 207,241 44,445 108.3 Strong Argillic Monomict Andesite Breccia 0.01 Trench SIMTR1106* 45 50 5 207,238 44,441 107.8 Strong Argillic Monomict Andesite Breccia 0.01 Trench SIMTR1106* 50 55 5 207,234 44,438 108.4 Moderate Argillic Monomict Andesite Breccia 0.01 Trench SIMTR1106* 55 60 5 207,230 44,435 109.3 Moderate Argillic Andesite Intrusive 0.01 Trench SIMTR1106* 60 65 5 207,225 44,435 111.0 Moderate Argillic Monomict Andesite Breccia 0.03 Trench SIMTR1106* 65 70 5 207,220 44,435 110.0 Moderate Argillic Andesite Intrusive 0.01 Trench SIMTR1106* 70 75 5 207,215 44,437 108.4 Moderate Argillic Monomict Andesite Breccia 0.01 Trench SIMTR1106* 75 80 5 207,210 44,438 107.6 Strong Argillic Andesite Intrusive 0.03 Trench SIMTR1106* 80 85 5 207,206 44,441 107.3 Strong Argillic Monomict Andesite Breccia 0.02 Trench SIMTR1106* 85 90 5 207,204 44,445 106.0 Strong Argillic Monomict Andesite Breccia 0.02 Trench SIMTR1106* 90 95 5 207,204 44,450 105.1 Strong Argillic Monomict Andesite Breccia 0.04 Trench SIMTR1106* 95 100 5 207,203 44,455 105.6 Strong Argillic Monomict Andesite Breccia 0.02 Trench SIMTR1106* 100 105 5 207,203 44,460 106.6 Strong Argillic Monomict Andesite Breccia 0.05 Trench SIMTR1106* 105 110 5 207,203 44,465 106.5 Strong Argillic Monomict Andesite Breccia 0.01 Trench SIMTR1106* 110 115 5 207,203 44,470 105.2 Strong Argillic Monomict Andesite Breccia 0.06 Trench SIMTR1106* 115 120 5 207,204 44,475 106.5 Strong Argillic Monomict Andesite Breccia 0.05 Trench SIMTR1106* 120 125 5 207,207 44,479 105.1 Strong Argillic Monomict Andesite Breccia 0.06 Trench SIMTR1106* 125 130 5 207,210 44,483 104.4 Moderate Argillic Monomict Andesite Breccia 0.02 NOTES: * Site Lab Results Co-ordinates are interval end points
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St Barbara Quarterly Report / Q4 June FY26 Page 26 of 32 Table 3 Cont: New Simberi Trench Assay Results – Simberi Island, Papua New Guinea. Sample Type Trench No From m To m Interval m North m East m RL m Lith Code Gold Grade Au g/t Trench SIMTR1106* 130 135 5 207,214 44,486 104.3 Moderate Argillic Monomict Andesite Breccia 0.01 Trench SIMTR1106* 135 140 5 207,218 44,488 104.6 Moderate Argillic Monomict Andesite Breccia 0.1 Trench SIMTR1106* 140 145 5 207,223 44,491 105.2 Moderate Argillic Monomict Andesite Breccia 0.1 Trench SIMTR1106* 145 150 5 207,227 44,493 106.0 Weak Argillic Andesite Intrusive 0.02 Trench SIMTR1106* 150 155 5 207,232 44,495 106.3 Weak Argillic Andesite Intrusive 0.02 Trench SIMTR1106* 155 160 5 207,236 44,498 105.6 Weak Argillic Monomict Andesite Breccia 0.01 Trench SIMTR1106* 160 165 5 207,239 44,502 104.5 Weak Argillic Monomict Andesite Breccia 0.02 Trench SIMTR1106* 165 170 5 207,243 44,505 101.7 Weak Argillic Monomict Andesite Breccia 0.06 Trench SIMTR1106* 170 175 5 207,243 44,510 101.6 Weak Argillic Monomict Andesite Breccia 0.02 Trench SIMTR1106* 175 180 5 207,242 44,515 101.7 Weak Argillic Monomict Andesite Breccia 0.02 Trench SIMTR1106* 180 185 5 207,241 44,520 104.0 Weak Argillic Monomict Andesite Breccia 0.01 Trench SIMTR1106* 185 190 5 207,240 44,525 103.9 Weak Argillic Monomict Andesite Breccia 0.04 Trench SIMTR1106* 190 195 5 207,239 44,530 103.0 Weak Argillic Monomict Andesite Breccia 0.02 Trench SIMTR1106* 195 200 5 207,237 44,535 103.0 Weak Argillic Monomict Andesite Breccia 0.04 Trench SIMTR1106* 200 205 5 207,235 44,539 101.6 Weak Argillic Monomict Andesite Breccia 0.03 Collar SIMTR1106* 205 210 5 207,232 44,543 100.9 Weak Argillic Monomict Andesite Breccia 0.02 Trench SIMTR1106* 210 215 5 207,229 44,547 98.8 Weak Argillic Monomict Andesite Breccia 0.04 Trench SIMTR1106* 215 220 5 207,226 44,551 96.5 Weak Argillic Monomict Andesite Breccia 0.05 Trench SIMTR1106* 220 225 5 207,224 44,555 96.4 Moderate Argillic Monomict Andesite Breccia 0.04 Trench SIMTR1106* 225 230 5 207,223 44,560 96.0 Moderate Argillic Monomict Andesite Breccia 0.06 Trench SIMTR1106* 230 235 5 207,221 44,565 96.2 Moderate Argillic Monomict Andesite Breccia 0.03 Trench SIMTR1106* 235 240 5 207,219 44,569 99.8 Weak Argillic Monomict Andesite Breccia 0.02 Collar SIMTR1106* 240 245 5 207,216 44,574 99.4 Weak Argillic Monomict Andesite Breccia 0.05 Trench SIMTR1106* 245 250 5 207,213 44,577 101.5 Weak Argillic Monomict Andesite Breccia 0.02 Trench SIMTR1106* 250 255 5 207,210 44,581 102.8 Weak Argillic Andesite Intrusive 0.04 Trench SIMTR1106* 255 260 5 207,205 44,584 104.6 Weak Argillic Andesite Intrusive 0.05 Trench SIMTR1106* 260 265 5 207,201 44,587 105.3 Weak Argillic Andesite Intrusive 0.09 Trench SIMTR1106* 265 270 5 207,197 44,590 105.3 Weak Argillic Andesite Intrusive 0.05 Trench SIMTR1106* 270 275 5 207,193 44,593 107.1 Weak Argillic Andesite Intrusive 0.06 Trench SIMTR1106* 275 280 5 207,190 44,596 105.9 Weak Argillic Andesite Intrusive 0.1 Collar SIMTR1107* 0 N/A 207,145 44,639 101.2 Trench SIMTR1107* 0 5 5 207,147 44,644 100.3 Soil 0.08 Trench SIMTR1107* 5 10 5 207,146 44,649 99.9 Oxidised clay (limonite/heamatite clay) 0.05 Trench SIMTR1107* 10 15 5 207,146 44,654 99.2 Oxidised clay (limonite/heamatite clay) 0.05 Trench SIMTR1107* 15 20 5 207,148 44,658 97.9 Strong Argillic Andesite Intrusive 0.06 Trench SIMTR1107* 20 25 5 207,152 44,662 97.2 Strong Argillic Andesite Intrusive 0.01 Trench SIMTR1107* 25 30 5 207,155 44,666 97.5 Moderate Argillic Andesite Intrusive 0.01 Trench SIMTR1107* 30 35 5 207,158 44,669 98.2 Moderate Argillic Andesite Intrusive 0.06 Trench SIMTR1107* 35 40 5 207,161 44,673 99.1 Moderate Argillic Andesite Intrusive 0.24 Trench SIMTR1107* 40 45 5 207,165 44,677 99.5 Moderate Argillic Andesite Intrusive 0.05 Trench SIMTR1107* 45 50 5 207,168 44,681 101.0 Moderate Argillic Andesite Intrusive 0.01 Trench SIMTR1107* 50 55 5 207,172 44,684 99.1 Moderate Argillic Andesite Intrusive 0.04 Trench SIMTR1107* 55 60 5 207,175 44,688 102.2 Weak Argillic Monomict Andesite Breccia 0.05 Trench SIMTR1107* 60 65 5 207,176 44,693 103.9 Moderate Argillic Monomict Andesite Breccia 0.04 Trench SIMTR1107* 65 70 5 207,176 44,698 105.7 Strong Argillic Monomict Andesite Breccia 0.03 Trench SIMTR1107* 70 75 5 207,173 44,702 107.8 Strong Argillic Monomict Andesite Breccia 0.11 Trench SIMTR1107* 75 80 5 207,169 44,706 108.2 Strong Argillic Monomict Andesite Breccia 0.05 Trench SIMTR1107* 80 85 5 207,166 44,709 108.2 Strong Argillic Monomict Andesite Breccia 0.06 Trench SIMTR1107* 85 90 5 207,163 44,713 108.1 Strong Argillic Monomict Andesite Breccia 0.01 Trench SIMTR1107* 90 95 5 207,159 44,717 107.0 Weak Argillic Monomict Andesite Breccia 0.05 Collar SIMTR1108* 0 N/A 207,174 44,719 101.5 Trench SIMTR1108* 0 5 5 207,174 44,724 100.9 Moderate Argillic Monomict Andesite Breccia 0.01 Trench SIMTR1108* 5 10 5 207,174 44,729 98.4 Moderate Argillic Monomict Andesite Breccia 0.02 Trench SIMTR1108* 10 15 5 207,173 44,734 96.0 Moderate Argillic Monomict Andesite Breccia 4.65 NOTES: * Site Lab Results Co-ordinates are interval end points
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St Barbara Quarterly Report / Q4 June FY26 Page 27 of 32 Table 3 Cont: New Simberi Trench Assay Results – Simberi Island, Papua New Guinea. Sample Type Trench No From m To m Interval m North m East m RL m Lith Code Gold Grade Au g/t Trench SIMTR1108* 15 20 5 207,172 44,739 95.6 Moderate Argillic Monomict Andesite Breccia 2.14 Trench SIMTR1108* 20 25 5 207,170 44,743 95.0 Moderate Argillic Polymict Breccia 1.95 Trench SIMTR1108* 25 30 5 207,168 44,748 93.9 Moderate Argillic Polymict Breccia 0.07 Trench SIMTR1108* 30 35 5 207,165 44,752 94.3 Tuff 0.04 Trench SIMTR1108* 35 40 5 207,163 44,756 94.4 Tuff 0.01 Trench SIMTR1108* 40 45 5 207,162 44,761 92.2 Tuff 0.03 Trench SIMTR1108* 45 50 5 207,161 44,766 90.6 Tuff 0.03 Trench SIMTR1108* 50 55 5 207,161 44,771 88.6 Tuff 0.03 Trench SIMTR1108* 55 60 5 207,163 44,776 89.2 Tuff 0.04 Trench SIMTR1108* 60 65 5 207,165 44,780 87.7 Strong Argillic Polymict Breccia 1.29 Trench SIMTR1108* 65 70 5 207,166 44,785 87.2 Strong Argillic Polymict Breccia 0.63 Trench SIMTR1108* 70 75 5 207,166 44,790 86.1 Strong Argillic Polymict Breccia 0.32 Trench SIMTR1108* 75 80 5 207,167 44,795 84.5 Moderate Argillic Polymict Breccia 0.71 Trench SIMTR1108* 80 85 5 207,167 44,800 82.7 Moderate Argillic Polymict Breccia 1.45 Trench SIMTR1108* 85 90 5 207,168 44,805 80.3 Weak Argillic Polymict Breccia 0.18 Trench SIMTR1108* 90 95 5 207,169 44,810 79.9 Weak Argillic Polymict Breccia 0.33 Trench SIMTR1108* 95 100 5 207,168 44,815 78.4 Weak Argillic Matrix-dominated Breccia 0.09 Trench SIMTR1108* 100 105 5 207,167 44,820 76.3 Unaltered/fresh Matrix-dominated Breccia 0.04 Trench SIMTR1108* 105 110 5 207,165 44,824 76.9 Unaltered/fresh Matrix-dominated Breccia 0.06 Collar SIMTR1109* 0 N/A 207,290 44,636 58.6 Trench SIMTR1109* 0 5 5 207,287 44,640 59.4 Weak Argillic Andesite Intrusive 1.25 Trench SIMTR1109* 5 10 5 207,284 44,644 58.0 Moderate Argillic Matrix-dominated Breccia 2.26 Trench SIMTR1109* 10 15 5 207,280 44,647 58.2 Moderate Argillic Matrix-dominated Breccia 5.1 Trench SIMTR1109* 15 20 5 207,276 44,648 57.6 Moderate Argillic Matrix-dominated Breccia 5.3 Trench SIMTR1109* 20 25 5 207,271 44,650 57.2 Moderate Argillic Matrix-dominated Breccia 0.07 Trench SIMTR1109* 25 30 5 207,266 44,651 56.8 Moderate Argillic Matrix-dominated Breccia 0.34 Trench SIMTR1109* 30 35 5 207,262 44,654 55.7 Weak Argillic Matrix-dominated Breccia 0.6 Trench SIMTR1109* 35 40 5 207,262 44,659 54.7 Weak Argillic Matrix-dominated Breccia 0.36 Trench SIMTR1109* 40 45 5 207,265 44,663 54.8 Moderate Argillic Matrix-dominated Breccia 0.16 Trench SIMTR1109* 45 50 5 207,269 44,666 53.0 Moderate Argillic Matrix-dominated Breccia 0.58 Trench SIMTR1109* 50 55 5 207,272 44,670 53.4 Strong Argillic Monomict Andesite Breccia 0.55 Trench SIMTR1109* 55 60 5 207,272 44,675 54.9 Strong Argillic Monomict Andesite Breccia 3.32 Trench SIMTR1109* 60 65 5 207,268 44,678 56.9 Strong Argillic Monomict Andesite Breccia 2.28 Trench SIMTR1109* 65 70 5 207,264 44,682 57.4 Weak Argillic Monomict Andesite Breccia 1.07 NOTES: * Site Lab Results Co-ordinates are interval end points
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St Barbara Quarterly Report / Q4 June FY26 Page 28 of 32 JORC Table 1 Checklist of Assessment and Reporting Criteria Drilling: Section 1 Sampling Techniques and Data – Simberi ML136 Criteria Commentary Sampling techniques • Diamond Drilling comprised PQ3 (83 mm) and HQ3 (61.1 mm) sized core collected using standard triple tubes. Half core was sampled on nominal 1 metre intervals with the lower or left half (looking downhole) of the core submitted for sample preparation and analysis. Competent core is half cored using an Almonte automated core saw whereas broken or highly weathered core is manually half cored with a masonry chisel. • Prior to 31 March 2025 and from 1 October 2025, including for this ASX Release, half core samples were fully prepared at the company's on-site sample preparation facility on Simberi Island with 150 g to 200 g pulps sent to ALS Laboratory in Townsville for further analysis. Pulp residues are stored in Townsville for six months follow ing assay before disposal. • Between 1 April 2025 and 30 September 2025, half core samples were fully barged to the Intertek Laboratory in Lae (PNG) for sample preparation. A 250 g pulp sample is sub split into a geochem packet for analysis in Lae and a 35g sample is sub split, packaged, and air freighted for multi element analysis to Intertek’s Perth Laboratory. Coarse and pulp residues are returned to Simberi for storage. Drilling techniques • Diamond drilling comprised PQ3 (83 mm) and HQ3 (61.1 mm) core recovered using a 1.5 m barrel. Drilling was completed by Quest Exploration Drilling (QED). When ground conditions permit, an ACT Digital Core Orientation Instrument was used by the contractor to orientate the HQ3 core. Drill sample recovery • Diamond drilling recovery percentages were measured by comparing actual metres recovered per drill run versus metres recorded on the core blocks. Recoveries averaged >98 % with increased core loss present in fault zones and zones of strong weathering/alteration. Logging • Diamond holes are qualitatively geologically logged for lithology, structure and alteration and qualitatively and quantitatively logged for veining and sulphide mineralogy. Diamond holes are geotechnically logged with the following attributes qualitatively recorded - strength, infill material, weathering, and shape. Whole core and half core photography is completed on wet core. • All holes are logged in their entirety and data recorded in templated excel workbook prior to being uploaded to the company’s secure SQL database. Sub-sampling techniques and sample preparation • All diamond drill core was half cored with the lower or left half (looking downhole) submitted for sample preparation and analysis. • Prior to 31 March 2025 and from 1 October 2025 including for this ASX Release: • All drill samples were prepared at the company’s on- site sample preparation facility. After oven drying for a minimum 8 hours, sample material undergoes initial crushing in a Terminator Jaw Crusher to achieve particle size <2 mm. For samples weighing in excess of 1 kg, a 0.8 kg to 1.2 kg sample split is taken using a riffle splitter. Crushed samples of ~ 1 kg standardised weight are then completely pulverised in an Essa LM2 Pulveriser (90% passing 75 microns). Approximately 200 g of pulverised material is retained for assaying using a metal scoop to transfer material into analytical envelopes (pulp packets) before being sent to the ALS lab in Townsville. • F or internal reference, a second pulverised sub- sample (~100 grams) is analysed at the site lab using same QAQC reference materials as those sent to ALS lab. • Q uality control of s ample material prepared on site consists of insertion of two (non-certified) blank control samples at the start of each hole, and between each sample, any pulverised residue in the LM2 is discarded and the bowl vacuumed and wiped clean. • 150 g to 200 g pulp samples are then sent to ALS Laboratory in Townsville for assay via air freight. Pulp residues are stored in Townsville for six months following assay before disposal. • Between 1 April 2025 and 30 September 2025: • All drill samples were prepared at the at the Intertek laboratory in Lae, PNG. • The entire half core underwent drying at <105°C in an electric oven. Samples then pass through a 2- stage crushing process, firstly crushed to ~85% passing 10mm, followed by crushing in a fine crusher to 85% passing 2mm. 2 kg of the crushed material is rotary sub split and then pulverised in a LM5 pulveriser to 90% passing 75µm (Method PB04). • For internal reference, St Barbara inserted two in house blanks at the start of the batch and then inserted OREAS standard certified reference material (1:20). • A 250 g pulp sample is sub split into a geochem packet for analysis in Lae and a 35g sample is sub split, packaged, and air freighted for multi element analysis to Intertek’s Perth Laboratory. • Coarse and pulp residues are returned to Simberi for storage for re-assay if required.
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St Barbara Quarterly Report / Q4 June FY26 Page 29 of 32 Criteria Commentary Quality of assay data and laboratory tests • Prior to 31 March 2025 and from 1 October 2025 including for this ASX Release: • Preliminary assays are received from pulps analysed for Au at the Simberi Lab using Aqua Regia digestion with a 15 g charge and analysis by Atomic Absorption Spectrometry. • Final assays are received for pulps analysed for Au at ALS Townsville via 50 g Fire Assay Atomic Absorption Spectroscopy (AAS) finish (Au- AA26 method) and multi -element (Ag, As, S, Fe, Cu, Pb, Zn, Mo and Sb) by Aqua Regia digest followed by Inductively Coupled Plasma Atomic Emission Spectroscopy (IC P-AES) instrument read (ME-ICP41S method). • Analyses at both the Site Lab and ALS comprised QC including insertion of certified reference material (1:20); insertion of in-house blank control material (2 at the start of each job); and the insertion of lab duplicates (1:20 split from the initial jaw crushed material prepared by the site lab. QAQC results were assessed as each laboratory batch was received and again at resource estimation cycles. Results indicate that pulveriser bowls were adequately cleaned between samples. ALS Townsville insert certified standards, replicates, lab repeats and complete sizing checks (1:40) or higher as part of their internal QAQC protocols. • Between 1 April 2025 and 30 September 2025: • Assays are received for pulps analysed for Au via 50 g Fire Assay / AAS Finish (Method FA50 / AA) at Intertek’s Lae Laboratory. Multi-element analysis was completed via 1 g Aqua Regia Digest and OES and MS finish for 9 elements Ag, As, Cu, Fe, Mo, Pb, S, Sb, Zn (Method AR1 / MS) at Intertek’s Perth Laboratory. • St Barbara QAQC included the insertion of two in house blanks at the start of the batch and the insertion of OREAS standard certified reference material (1:20). St Barbara inserted OREAS standards (238b, 607c, 61h and 245) as matched to material type and grade approximation. • Intertek Laboratory QAQC involved the insertion of Reagent Blanks and Certified Reference Materials (1:25) and analytical pulp duplicates were assayed (1:25). • The Fire Assay gold analysis technique is considered a complete extraction method. The Aqua Regia digestion is considered a partial digestion technique that effectively dissolves metals not tightly bound within silicate structures. Verification of sampling and assaying • Sampling data is recorded electronically which ensures only valid non -overlapping data can be recorded. Assay and downhole survey data are subsequently merged electronically. All drill data is stored in a SQL database on secure company server. • No adjustments to assay data have been made. Location of data points • All drill collars were surveyed by company appointed surveyors using a DGPS in Tabar Island Grid (TIG) which is based on WGS84 ellipsoid and is GPS compatible. • All diamond drill holes were downhole surveyed using a Reflex EZ track single shot camera with the first reading at 10, 12, 13, 14 or 15 m and three at 30 m and then approximately every 30 m increments to the bottom-of-the hole where an end of hole survey is also taken or projected to end of hole from last down hole survey reading. Data spacing and distribution • Resource definition drilling to define Indicated Mineral Resources is completed on a nominal 30m x 40m pattern. This spacing is adequate to establish both geological and grade continuity for the Mineral Resource and Ore Reserve procedures. • Sampling is typically based on one-metre intervals with no compositing applied. Orientation of data in relation to geological structure • Drilling is orientated perpendicular to the major structures controlling the distribution of gold mineralisation . The orientation of the drilling ensures unbiased sampling of structures. Exceptions occur when topography restricts access and prevents mineralisation being tested from an optimal orientation. • In the Northeast Pigiput area mineralisation is interpreted to strike northeast -southwest and dip moderately to the northwest. In this area the optimum drill orientation is to drill to the southeast. • In the North and central Samat area mineralisation is interpreted to strike north- northeast and dip steeply to the west-northwest or east-southeast. In this area the optimum drill orientation is to drill to the west-northwest or east- southeast. • In the Southeast Samat area mineralisation is interpreted to strike west-northwest and dip moderately to steeply to the north-northeast. In this area the optimum drill orientation is to drill to the southwest. • In the Southwest Pigiput Area mineralisation is interpreted to strike north- northeast and dip steeply to the west - northwest. In this area the optimum drill orientation is to drill to the east-southeast. Sample security • Prior to 31 March 2025 and from 1 October 2025 including for this ASX Release: • Only company personnel or approved contractors are allowed on drill sites; drill core is only removed from drill site to secure core logging/processing facility within the gated exploration core yard; core is promptly logged, cut, and prepped on site. The samples sent to ALS are stored in locked and guarded storage facilities until receipted at the Laboratory. • Between 1 April 2025 and 30 September 2025: • Only company personnel or approved contractors are allowed on drill sites; drill core is only removed from drill site to secure core logging/processing facility within the gated exploration core yard; core is promptly logged, cut, and packaged on site. The samples sent to Intertek Lae are stored in locked and guarded storage facilities until receipted at the Laboratory. Audits or reviews • No audits or reviews of sampling protocols have been completed.
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St Barbara Quarterly Report / Q4 June FY26 Page 30 of 32 Drilling: Section 2 Reporting of Exploration Results – Simberi ML136 Criteria Commentary Mineral tenement and land tenure status • Tabar Islands Holding Limited (of which St Barbara Limited owns 50 %) has 100 % ownership of the three tenements over the Simberi Islands; ML136 on Simberi Island, EL609 which covers the remaining area of Simberi Island, as well as Tatau Island and Big Tabar Island and 4 sub-block EL2462 which covers part of Tatau and Mapua Islands. Refer to ASX Announcement dated 2 April 2026: Strategic Transaction with Lingbao Completed, Final Investment Decision Approved. Exploration done by other parties • CRA, BHP, Tabar JV (Kennecott, Nord Australex and Niugini Mining), Nord Pacific, Barrick and Allied Gold have all previously worked in this area. Nord Pacific followed by Allied Gold was instrumental in the discovery and delineation of the 5 main oxide and sulphide deposits at Simberi. • St Barbara has undertaken exploration on the tenements since acquisition from Allied Gold in September 2012. • St Barbara (through its wholly owned PNG subsidiary Nord Australex Nominees (PNG) Ltd) had an Option and Farm-In Agreement with Newcrest PNG Exploration Limited (a wholly owned subsidiary of Newcrest Mining Limited) between 2016 and 2019. During this time, exploration was conducted for Cu-Au porphyry deposits on tenements EL609 and EL2462 covering Tatau and Big Tabar Islands. Geology • The Tabar group of islands is located in the New Ireland Province, Papua New Guinea. The Tabar-Feni Island chain comprises a series of Pliocene to Recent volcanoes that occupy a fore- arc position in the New Ireland Basin, part of the Bismarck archipelago. Volcanism in the area began about 3.7 Ma ago, coeval with the initiation of back -arc spreading in the Manus basin. Volcanism in the Bismarck archipelago is dominantly calc -alkaline to high K calc - alkaline generated as a result of stalled subduction and partial melting of the Pacific plate beneath the Indo- Australian plate along the Manus-Kilinailau trench. • The Simberi gold deposits are low sulphidation, intrusion related adularia- sericite epithermal gold deposits. The dominant host rocks for mineralisation are andesites, volcaniclastics and lesser porphyries. Gold mineralisation is generally associated with sulphides or iron oxides occurring within a variety of fractures, such as simple fracture in- fills, single vein coatings and crackle brecciation in the more competent andesite units, along andesite/polymictic breccia contact margins as well as sulphide disseminations. Several holes in the area between Sorowar and Pigiput intersected zones of between 20 m and 100 m of semi continuous carbonate ± quartz base metal / Au veining, similar in style to mineralisation occurring on Tatau and Big Tabar islands to the south, which are also prospective for Porphyry Cu/Au deposits. Drill hole Information • Drill hole information is included in intercept table outlining collar position obtained by DGPS pickup, hole dip and azimuth acquired from a downhole surveying camera as discussed in Section 1, composited mineralised intercepts lengths and depth as well as hole depth. Data aggregation methods • All results have been reported. • No top-cutting has been applied. • No assumptions on metal equivalents have been made. • Intercepts from the ALS (Townsville) and Intertek (Lae / Perth) laboratories for gold only epithermal mineralisation, comprise broad down hole intercepts reported as length weighted averages using a cut-off of 0.6 g/t Au, minimum width of 2 m, and a minimum grade*length of 2.5 gmpt (gram metre per tonne). Such intercepts may include material below cut-off but no more than 5 sequential metres of such material and except where the average drops below the cut-off. Supplementary cut -offs, of 1.0 g/t, 2.5 g/t, 5.0 g/t and 10.0 g/t Au may be used to highlight higher grade zones and spikes within the broader aggregated interval. Single assays intervals are reported only where ≥2.5 g/t Au and ≥1 m down hole. • Core loss is assigned the same grade as the sample grade; no high- grade cut is applied; grades are reported to one decimal figure for g/t results. Relationship between mineralisation widths and intercept lengths • Down hole length was reported for all holes. • Simberi lodes display high variability in orientation and complex geometries because of the interplay of veining, brecciation intensity, host lithology and oxidation fronts. • At the Darum Waste Rock Dump, in Q3 FY26, one hole (SDH724) was drilled towards the southeast (135°) at an angle of 60° from horizontal roughly perpendicular to an interpreted potential northeast strike to mineralisation. • At Northeast Pigiput, two resource definition drill holes (SDH729 and SDH730) were drilled to the southeast (between 110° and 135°) and at an angle of between 57° and 60° from the horizontal, roughly perpendicular to an interpreted potential northeast strike to mineralisation. • At Southeast Samat, six resource definition / exploration drill holes ( SDH725 to SDH728, SDH731 and SDH735) were drilled southwest (azimuth 220°) and at an angle of 60° from the horizontal and one hole (SDH732) was drilled toward the northeast (azimuth 40°) at an angle of 65° from horizontal. The drilling is roughly perpendicular to an interpreted potential southeast strike to mineralisation. One exploration drill hole at Southeast Samat (SDH734) was drilled toward the southeast (azimuth 130°) and at an angle of 60° from the horizontal with the orientation constrained due to topography and access. • At Northeast Andora, one exploration hole at (SDH733) was drilled toward the southeast (azimuth 135°) at an angle of 60° from horizontal. • At Southwest Pigiput, in Q3 FY26, two infill resource definition drill holes (SDH722 and SDH723) were drilled towards the southeast (azimuth 135°) at an angle of 60° from horizontal. Diagrams • Included in the body of the report. Drill holes SDH709, SDH711 and SDH733 are not shown on the diagrams. Balanced reporting • Details of all holes material to Exploration Results are reported in the intercept tables. This report covers 16 holes (SDH712 and SDH715 to SDH729) from the 6, 325.6 metre FY26 resource definition, exploration and sterilisation diamond drilling program. This includes assay results for eight new holes (SDH722 to SDH729) as well as updated ALS assay results for eight holes (SDH712, SDH715 to SDH721) previously reported from the site laboratory in Q3 FY26. • Assay results from eight Samat exploration/resource definition holes, five Darum Waste Rock dump sterilisation drill holes, three Southwest Pigiput exploration/sterilisation holes, one Northeast Pigiput resource definition holes, and one Pigiput Northeast Trend resource definition hole are reported in Table 1. Other substantive exploration data • Included in the body of the report.
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St Barbara Quarterly Report / Q4 June FY26 Page 31 of 32 Criteria Commentary Further work • Included in the body of the report. Assay results are pending for six Q4 FY26 drill holes including one Northeast Pigiput resource definition hole (SDH730), four Samat resource definition or exploration holes (SDH731, SDH732 SDH734 and SDH735) and one Northeast Andora exploration hole (SDH733). • Further diamond drilling will be designed and conducted once all the assay results have been returned from the programs described above. Additional exploration drilling is planned in FY27 targeting extensions to mineralisation at Samat and Andora deposits. Trenching: Section 1 Sampling Techniques and Data – Simberi ML136 Criteria Commentary Sampling techniques • Sampling of trenches was done over measured intervals of 5 metres. A geo-pick was used to collect a continuous channel sample from the trench faces across the designated interval with the samples collected in calico bags. • For trenches SIMTR1073 to 1076, samples (3 to 5 kg) were placed in calico bags, then larger polyweave bags and palletised for dispatch to the Intertek laboratory in Lae, PNG. • For trenches SIMTR1077 to SIMTR1115, samples (3 to 5 kg) were placed in calico bags, then submitted at the company onsite sample preparation facility on Simberi Island. Trenching techniques • Mechanised trenches were dug by an excavator or dozer exposing up to 5 meters of trench wall. Drill sample recovery • No RC or diamond drilling was undertaken and as a result no drilling is being reported. • Trench sampling techniques have been described above. Logging / Mapping • All trenches were qualitatively geologically mapped for lithology, weathering, structure and alteration. Sub-sampling techniques and sample preparation • For trenches SIMTR1073 to SIMTR1076, samples underwent drying at <105°C in an electric oven. Samples then passed through a 2-stage crushing process, firstly crushed to ~85% passing 10mm, followed by crushing in a fine crusher to 85% passing 2mm. 2 kg of the crushed material is rotary sub split and then pulverised in a LM5 pulveriser to 90% passing 75µm (Method PB04). A 250 g pulp sample is sub split into a geochem packet for analysis in Lae and a 35g sample is sub split, packaged, and air freighted for multi element analysis to Intertek’s Perth Laboratory. • For trenches SIMTR1077 to SIMTR1115, samples (3 to 5 kg) are routinely submitted for total pulverisation (85 % passing <75 μm) at the company onsite sample preparation facility on Simberi Island. This involved drying at <105°C in an electric oven, then on-site sample preparation (jaw crushed, disk mill pulverised and then split) to produce a 100 g pulp sample. A 15 g charge was then extracted from the pulp for preliminary Au analyses at St Barbara’s Simberi Laboratory. The remaining ~85 g pulp samples are stored at Simberi site for re-assay if required. Quality of assay data and laboratory tests • For trenches SIMTR1073 to SIMTR1076, samples were analysed for gold via 50 g Fire Assay / AAS Finish (Method FA50 / AA) at Intertek’s Lae Laboratory. Multi-element analysis was completed via 1 g Aqua Regia Digest and OES and MS finish for 9 elements Ag, As, Cu, Fe, Mo, Pb, S, Sb, Zn (Method AR1 / MS) at Intertek’s Perth Laboratory. • For trenches SIMTR1077 to SIMTR1115, samples were analysed for gold at the Simberi Lab using Aqua Regia digestion with a 15 g charge and analysis by Atomic Absorption Spectrometry. • QC during the quarter included the insertion of two in-house blanks at the start of each batch of trench samples, the insertion of certified gold standards (1:50) and crush duplicates collected during sample preparation (1:20). • Over the duration of the quarter St Barbara inserted OREAS standards 252b, 238b and 607c as matched to material type and grade approximation for Simberi trenches. • The Fire Assay gold analysis technique is considered a complete extraction method. The Aqua Regia digestion is considered a partial digestion technique that effectively dissolves metals not tightly bound within silicate structures. Verification of sampling and assaying • Sampling data is recorded electronically which ensures only valid non-overlapping data can be recorded. Assay and trench survey data are subsequently merged electronically. All data is stored in a SQL database on secure company server. Location of data points • All Simberi Island trenches were initially surveyed by a handheld GPS to capture the trench start point. The GPS used the Tabar Island Grid (TIG) which is based on WGS84 ellipsoid. The path of the trench from the initial start point to the end was surveyed by Tape & Compass method. Trench interval coordinates were then generated using basic trigonometry. Final TIG RLs are generated by registering the samples over a combined Lidar and survey pickup mined surface (Simberi). Data spacing and distribution • Trench data spacing is irregular and broad spaced. Orientation of data in relation to geological structure • Where preceding surface mapping and sampling of trenches have contributed to the understanding of outcropping geological structures, trenching and sampling has been undertaken to extend the strike length of the mapped structure. However, in many of the areas the lode orientation is poorly understood. Sample security • Only trained company personnel were allowed to collect the samples. All samples were held within a secure company building before dispatch. Trench samples from SIMTR1073 to SIMTR1076 were prepared at the Intertek laboratory preparation facility in Lae. Trench samples from SIMTR1077 to SIMTR1115 were prepared on site at the sample preparation facility. Audits or reviews • No audits or reviews of sampling protocols have been completed.
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St Barbara Quarterly Report / Q4 June FY26 Page 32 of 32 Trenching: Section 2 Reporting of Exploration Results – Simberi ML136 Criteria Commentary Mineral tenement and land tenure status • Tabar Islands Holding Limited (of which St Barbara Limited owns 50 %) has 100 % ownership of the three tenements over the Simberi Islands; ML136 on Simberi Island, EL609 which covers the remaining area of Simberi Island, as well as Tatau Island and Big Tabar Island and 4 sub-block EL2462 which covers part of Tatau and Mapua Islands. Refer to ASX Announcement dated 2 April 2026: Strategic Transaction with Lingbao Completed, Final Investment Decision Approved. Exploration done by other parties • CRA, BHP, Tabar JV (Kennecott, Nord Australex and Niugini Mining), Nord Pacific, Barrick and Allied Gold have all previously worked in this area. Nord Pacific followed by Allied Gold was instrumental in the discovery and delineation of the 5 main oxide and sulphide deposits at Simberi. Geology • The Simberi gold deposits are low sulphidation, intrusion related adularia-sericite epithermal gold deposits. The dominant host rocks for mineralisation are andesites, volcaniclastics and lesser porphyries. Gold mineralisation is generally associated with sulphides or iron oxides occurring within a variety of fractures, such as simple fracture in-fills, single vein coatings and crackle brecciation in the more competent andesite units, along andesite/polymictic breccia contact margins as well as sulphide disseminations. On Tatau and Big Tabar Islands, located immediately south of Simberi, potential also exists for porphyry Cu-Au, epithermal quartz Au-Ag and carbonate-base metal Au mineralisation. Trench Information • Included in the report text and annotated on diagrams. Data aggregation methods • For Simberi trenches, broad trench intercepts are reported as length weighted averages using a cut-off of 0.6 g/t Au and a minimum grade*length of 2.5 gmpt. Such intercepts may include material below cut-off but no more than 5 sequential meters of such material and except where the average drops below the cut-off. • For Simberi trenches, using the same criteria for included sub-grade, supplementary cut-offs, of 1.0 g/t Au, 2.5 g/t Au, 5.0 g/t Au and 10 g/t Au, may be used to highlight higher grade zones and spikes within the broader aggregated interval. Single assays intervals are reported only where ≥1.0 g/t and ≥5 m trench length is intercepted. Grades are reported to 1 decimal figure & no high-grade cut is applied. • Grades are reported to one decimal figure for g/t results, zero decimals for ppb results and no metal equivalent values are used for reporting exploration results. Relationship between mineralisation widths and intercept lengths • Trench intercepts are sampled along the length of the trench and are reported for all trenches; true width is not reported. Diagrams • Included in the body of the report. All trenches except for SIMTR1078 to SIMTR1084 and SIMTR1090 to SIMTR1091 plot within the figure boundaries. Balanced reporting • Figures when included show all sample sites material and immaterial to Exploration Results. Other substantive exploration data • Included in the body of the report. Further work • Included in the body of the report.