Brightstar Resources Hits 167m at 2.07g/t Gold at Bull Oak Ahead of 2026 PFS
Key Takeaways
- The standout intercept of 167m @ 2.07g/t Au from 104m in hole BORC26042 is the headline result from Bull Oak's completed infill program, designed specifically to upgrade the resource from Inferred to Indicated ahead of the Sandstone PFS.
- Bonanza-grade hits of 265g/t Au and 242g/t Au sit nested within the bulk granodiorite envelope, giving Bull Oak a dual character — high-grade shoots inside a broad, open-pittable mineralised body — that is rare in a single deposit.
- The deepest hole in the program, BORC26044, ended in mineralisation at 280 metres depth and remains open, signalling the deposit boundary has not yet been found and resource growth potential continues downward.
- Brightstar draws an explicit geological parallel between Bull Oak and the adjacent 1.45Moz Two Mile Hill-Shillington deposit, both hosted in the same felsic intrusive rock type within the Sandstone Greenstone Belt.
- The maiden Sandstone PFS — the first economic assessment of the consolidated 3.6Moz land package — is targeted for release before end-2026, with the Goldfields Hub FS (A$606M NPV8, 74% IRR, 75,000oz/year) providing a value benchmark for what a Sandstone study could represent.
Bull Oak delivers 167m @ 2.07g/t Au as Sandstone PFS takes shape
Brightstar Resources (ASX: BTR) has received final assay results from its Bull Oak infill RC and diamond drilling program at the Sandstone Gold Project, with the standout result being 167m @ 2.07g/t Au from 104m in hole BORC26042. The drilling was specifically designed to upgrade the Mineral Resource classification from Inferred to Indicated, feeding directly into the upcoming Pre-Feasibility Study (PFS). Bull Oak hosts a current Mineral Resource Estimate (MRE) of 10.5Mt @ 1.0g/t Au for 322koz Au and sits within the broader 3.6Moz @ 1.4g/t Au Sandstone Gold Project. The PFS, representing the first economic assessment of the consolidated Sandstone land package, is targeted for release before the end of 2026.
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Standout intercepts from the Bull Oak program
These final assay results follow an earlier batch reported on 7 September 2026 and complete the infill program. The mineralisation at Bull Oak has a dual character worth understanding: discrete bonanza-grade zones sit nested within broad, bulk intervals hosted in the granodiorite intrusion. Both dimensions matter for how the deposit is eventually developed.
High-grade hits within the granodiorite
The programme returned a series of high-grade intervals that underline the exceptional grade potential within the bulk envelope:
- 10m @ 25.0g/t Au from 120m, incl. 1m @ 242g/t Au from 127m (BORC26042)
- 14.5m @ 10.8g/t Au from 300m, incl. 0.5m @ 265g/t Au from 303.5m (BODD26010)
- 14m @ 9.13g/t Au from 209m, incl. 1m @ 113g/t Au from 217m (BORC26045)
- 7m @ 9.04g/t Au from 111m, incl. 1m @ 57.5g/t Au from 111m (BORC26041)
- 42m @ 2.91g/t Au from 280m, incl. 1m @ 60.7g/t Au from 280m (BORC26044) — one of the deepest holes drilled at Bull Oak, ending in mineralisation and remaining open at depth
Bulk granodiorite intervals — the open pit case
Alongside those high-grade hits, the program returned substantial unconstrained bulk intervals within the host granodiorite intrusion. These reflect the broader mineralised envelope and are critical inputs for open pit mine modelling in the PFS.
| Hole ID | From (m) | Drilled Interval (m) | Grade (g/t Au) | Status |
|---|---|---|---|---|
| BORC26042 | 104 | 167m | 2.07 | |
| BORC26045 | 147 | 124m | 1.45 | |
| BORC26044 | 247 | 75m | 1.78 | Open at depth |
| BORC26041 | 45 | 94m | 1.00 |
The adjacent BIF and basalt sequence also returned high-grade results, including 7m @ 9.77g/t Au from 40m (incl. 1m @ 61.8g/t Au from 43m) in BORC26042, and 8m @ 3.83g/t Au from 35m in BODD26009. These hits signal that gold mineralisation extends beyond the main granodiorite intrusion, adding further breadth to the deposit.
What makes Bull Oak tick — the geology behind the grades
Bull Oak is what geologists call a felsic intrusive-hosted gold deposit. In plain terms, that means gold has concentrated within a body of coarse-grained igneous rock (the granodiorite) that intruded into older surrounding rocks. The gold occurs in networks of quartz veins running through that intrusion, with the highest grades concentrated where those veins are most densely developed.
The announcement draws an explicit comparison to the nearby Two Mile Hill-Shillington deposit, which hosts an MRE of 1.45Moz @ 1.8g/t Au. Both deposits share the same host rock type, the same geological setting within the Sandstone Greenstone Belt, and the same style of quartz vein mineralisation. That comparison matters to investors because it provides a scale reference: Two Mile Hill is already a substantial deposit in the same geological package, using the same structural controls.
Bull Oak has grown approximately 4x in MRE size since Brightstar acquired it, reaching 322koz. Critically, the deposit remains open at depth — meaning drilling has not yet found the bottom of the mineralised intrusion. BORC26044, one of the deepest holes in this program, ended in mineralisation and remains open at depth. That open-depth characteristic is the same feature that supported significant resource growth at Two Mile Hill, and it signals the Bull Oak boundary is still expanding downward.
The Two Mile Hill drilling program has already returned a 305m continuous gold intercept that ended without finding the ore boundary, a result that directly underpins the comparison management draws between Two Mile Hill and Bull Oak’s open-depth characteristic.
Director quote
Alex Rovira, Managing Director
“The latest Bull Oak results contain further spectacular grades, including another bonanza intercept of 265g/t Au. These results are the final assays to be received from the infill drilling program at Bull Oak and follow on from the previously reported assays which included the highest single assay Brightstar has intersected at Sandstone of 751g/t Au.
Bull Oak shares similar geological attributes to the 1.45Moz Two Mile Hill-Shillington deposit, with gold mineralisation in both deposits being hosted largely within felsic intrusives. With broad intercepts such as 167m @ 2.07g/t Au, Bull Oak presents as a material potential open pit ore source for future Sandstone mining operations. Importantly, as with Two Mile Hill, Brightstar has yet to close off Bull Oak at depth, with the mineralised felsic intrusion remaining open at depth.
Results from this drilling will be incorporated into the next Bull Oak Mineral Resource update, which we expect will materially increase the Indicated component ahead of the upcoming Sandstone PFS. Work on this important study, the first economic assessment of the consolidated Sandstone land package, is progressing with release targeted before the end of 2026.
With the completion of the PFS drilling at Sandstone, the RC drill rig has now moved to test some exciting, early-stage exploration targets across the Sandstone Project. The diamond rig has been mobilised to the Menzies Project to carry out exploration drilling to test depth extensions at several key deposits, including near-term mines Yunndaga and Lady Shenton.
Two diamond rigs are targeted to mobilise to the Two Mile Hill deposit later this month to continue the drill out of Two Mile Hill, particularly focused on infill drilling the Shirvington Zone at depth.
We look forward to providing further updates and assays results in the coming weeks.”
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What comes next — MRE update, PFS, and the broader drill campaign
With the final Bull Oak assays now in hand, a clear sequence of catalysts is taking shape for the remainder of 2026. The upcoming milestones disclosed in the announcement include:
- Bull Oak MRE update — all final assays are now received; the update is expected to materially increase the Indicated component of the resource, supporting the PFS inputs.
- Sandstone PFS — the first economic assessment of the consolidated Sandstone land package, with release targeted before the end of 2026.
- RC rig redirected to early-stage exploration targets across the broader Sandstone Project, following completion of the PFS infill campaign.
- Diamond rig mobilised to Menzies Project — targeting depth extensions at Yunndaga and Lady Shenton, both identified as near-term mines.
- Two diamond rigs targeted to mobilise to Two Mile Hill later in October 2026, focused on infill drilling the Shirvington Zone at depth.
Shirvington Zone drilling at Two Mile Hill has already confirmed 53 visible gold occurrences at depth, reinforcing the scale potential of the same geological system that Bull Oak is being compared against.
The company is running three rigs simultaneously (2x RC, 1x diamond) across multiple project hubs, with a string of assay results and study milestones expected before year-end. To understand what the Sandstone PFS could represent in value terms, the Goldfields Hub Feasibility Study (published January 2026) provides a useful benchmark: it outlined production of more than 75,000oz per year for six years, with approximately A$1 billion in life-of-mine cashflows, an A$606M NPV8, and a 74% IRR. Construction of the processing plant is underway, with gold production targeted for the June quarter of CY27. The Sandstone PFS, when it arrives, is expected to be the next major value inflection point for the company.
Ready to Explore the Full Investment Case for Brightstar’s Sandstone Gold Project?
Bull Oak’s final assay results, headlined by 167m @ 2.07g/t Au and bonanza intercepts reaching 265g/t Au, are now feeding directly into a resource upgrade and the maiden Sandstone Pre-Feasibility Study, both targeted for delivery before the end of 2026. With the deposit remaining open at depth and comparisons drawn to the 1.45Moz Two Mile Hill-Shillington deposit next door, the scale potential here is still expanding.
For a deeper look at the project geology, upcoming catalysts, and what this drilling program means for Brightstar’s resource trajectory, explore the full Brightstar Resources coverage on Discovery Alert to stay ahead of the next announcement.