Brightstar Hits 751g/t Gold at Bull Oak Setting New Sandstone High Ahead of PFS
Key Takeaways
- Hole BORC26036 returned 7m @ 119g/t Au from 199m, including a record 1m @ 751g/t Au — the highest single assay Brightstar has recorded across the entire Sandstone project.
- The infill campaign of 39 RC holes (~7,500m) and 11 diamond holes (~2,900m) is specifically designed to upgrade Bull Oak's resource classification from Inferred to Indicated, a prerequisite for inclusion in the upcoming Sandstone PFS.
- Bull Oak's MRE currently stands at 10.5Mt @ 1.0g/t Au for 322koz Au — approximately four times larger than when Brightstar acquired the deposit — and remains open at depth.
- Multiple assay results remain pending, including BORC26031, 26032, 26039–26045 and BODD26006–26013, with the updated MRE and Sandstone PFS both targeted for release before end of 2026.
- The nearby Two Mile Hill deposit, 8km southeast and sharing identical granodiorite-hosted geology, carries an MRE of 731koz @ 1.6g/t Au, providing a direct local analogue for Bull Oak's growth potential.
Spectacular high-grade gold grades headline Bull Oak infill drill results
Brightstar Resources (ASX: BTR) has returned some of its most striking gold assays yet from the Bull Oak deposit at the Sandstone Gold Project, with hole BORC26036 delivering 7m @ 119g/t Au from 199m, including a standout 1m @ 751g/t Au from 202m. That single-sample result is the highest assay Brightstar has recorded at Sandstone, and it arrives during an active infill programme designed to lift resource confidence ahead of an imminent Pre-Feasibility Study (PFS). Three drill rigs remain operating on site.
Other headline intercepts from this phase of results include:
- 21m @ 3.83g/t Au from 262m, including 1m @ 27.1g/t Au (BORC26010)
- 7m @ 12.2g/t Au from 87m, including 1m @ 82.7g/t Au (BORC26029)
- 5m @ 8.22g/t Au from 237m, including 1m @ 36.7g/t Au (BORC26009)
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Q1 FY27 Bull Oak drilling program — what was drilled and why it matters
The purpose of this programme goes beyond chasing high-grade hits. Brightstar designed the infill campaign specifically to upgrade a significant portion of the Bull Oak Mineral Resource Estimate (MRE) from the Inferred to Indicated classification, a requirement for the resource to be incorporated into the Sandstone PFS, which is targeted for release before the end of 2026.
The campaign comprised 39 RC holes (~7,500m) and 11 diamond drill holes (~2,900m). Assay results reported here cover 28 RC holes and 3 diamond holes, with remaining holes — including BORC26031, 26032, 26039–26045 and BODD26006–26013 among others — still pending.
Two geological targets, one consistent high-grade story
Results are coming from two distinct zones. The host granodiorite intrusion is producing high-grade discrete pods sitting within broader zones of lower-grade bulk mineralisation. The unconstrained bulk intervals from the granodiorite illustrate the open pit potential clearly:
- 184m @ 1.00g/t Au from 135m (BORC26010)
- 169m @ 0.73g/t Au from 111m (BORC26009)
- 238m @ 0.55g/t Au from 68m (BORC26013)
The adjacent BIF and basalt package is also delivering meaningful results. BORC26014 returned 9m @ 7.39g/t Au from 26m, including 1m @ 56.3g/t Au from 30m, confirming mineralisation extends beyond the granodiorite itself.
| Hole ID | From (m) | Interval (m) | Grade (g/t Au) | Setting |
|---|---|---|---|---|
| BORC26036 | 199 | 7 | 119 (incl. 1m @ 751g/t) | Granodiorite |
| BORC26029 | 87 | 7 | 12.2 (incl. 1m @ 82.7g/t) | Granodiorite |
| BORC26010 | 262 | 21 | 3.83 (incl. 1m @ 27.1g/t) | Granodiorite |
| BORC26009 | 237 | 5 | 8.22 (incl. 1m @ 36.7g/t) | Granodiorite |
| BORC26010 | 194 | 19 | 1.76 (incl. 1m @ 18.8g/t) | Granodiorite |
| BORC26014 | 26 | 9 | 7.39 (incl. 1m @ 56.3g/t) | BIF-Basalt |
| BORC26025 | 87 | 7 | 3.78 (incl. 1m @ 22.2g/t) | BIF-Basalt |
Understanding felsic intrusive-hosted gold — why Bull Oak’s geology is so significant
A granodiorite is a type of igneous rock, similar in composition to granite, that forms when magma cools slowly deep within the earth. At Bull Oak, gold mineralisation is hosted within sheeted, shallowly east-dipping vein sets inside one of these granodiorite intrusions. The deposit style features discrete zones of very high-grade gold sitting within broader envelopes of lower-grade bulk mineralisation — a configuration that geologists understand well and that lends itself to open pit mining.
This matters because it is not a unique or puzzling deposit type. It is a well-documented, mineable geological setting, and Brightstar has a direct local analogue to point to: the Two Mile Hill-Shillington deposit, located just 8km to the southeast of Bull Oak, carries an MRE of 731koz @ 1.6g/t Au and shares an identical geological architecture.
Two Mile Hill drilling has already returned a headline 305m intercept at the deposit that shares Bull Oak’s granodiorite-hosted architecture, reinforcing management’s confidence that the felsic intrusive system running through the Sandstone tenure is capable of producing large, continuous mineralised envelopes.
Bull Oak currently hosts an MRE of 10.5Mt @ 1.0g/t Au for 322koz Au, and the deposit remains open at depth. It has grown approximately four times in MRE size since Brightstar acquired it, and it is being assessed as a significant open pit mining operation within the current PFS workstreams. The Two Mile Hill comparison is not just a geological footnote — it validates the potential for further resource growth and high-grade discovery as drilling continues to test depth extensions.
MD’s view — growth strategy centres on this deposit type
Managing Director Alex Rovira
“The latest Bull Oak results contain some spectacular grades, including the highest single assay Brightstar has intersected at Sandstone, 751g/t Au. Bull Oak is known to have similar geology to the larger Two Mile Hill Deposit, 8km to the southeast, so it is no surprise to see zones of very high grade mineralisation within a lower grade mineralised felsic intrusion, in this case a granodiorite.”
Rovira’s commentary makes clear that targeting felsic intrusive-hosted deposits is now a core pillar of Brightstar’s exploration strategy. Both Bull Oak and Two Mile Hill are being assessed for significant follow-up drilling, and nearby felsic intrusive analogues are being reviewed and advanced toward drill testing.
The broader Sandstone project is also seeing positive results from a secondary programme at the Havilah deposit. Significant intercepts from recent Havilah drilling include 4m @ 11.1g/t Au from 6m, including 1m @ 37.1g/t Au from 8m (HVRC26013), and 12m @ 2.24g/t Au from 3m (HVRC26009). These results were designed to infill a portion of the current Havilah Mineral Resource and test for down-dip and down-plunge extensions to the high-grade mineralisation.
What comes next — PFS, resource update and ongoing drilling
Brightstar has a clear pipeline of near-term catalysts that should keep the company in focus through the remainder of 2026:
- Updated Bull Oak Mineral Resource Estimate — Brightstar anticipates a material increase in the Indicated component once all assays from this infill programme are incorporated.
- Sandstone Pre-Feasibility Study — targeted for release before the end of 2026, drawing on the upgraded Bull Oak resource and ongoing workstreams across the 2.9Moz project.
- Remaining assay results pending — multiple RC and diamond holes are still outstanding, including BORC26031, 26032, 26039–26045 and BODD26006–26013, with further results expected in coming weeks.
- Follow-up drilling at Bull Oak and Two Mile Hill — both deposits are being assessed for significant step-out programmes to test depth extensions and the broader felsic intrusive system.
- Early-stage exploration at nearby analogues — similar felsic intrusives close to both deposits are being advanced toward drill testing as part of upcoming programmes.
Each of these items represents a discrete news trigger. For investors tracking BTR, the Sandstone PFS in particular stands as a landmark catalyst — it will be the first time the full 2.9Moz project is assessed through a formal feasibility framework.
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About Brightstar Resources
Brightstar Resources (ASX: BTR) is a Perth-based emerging gold producer with more than 4.5Moz of total Mineral Resources across its Goldfields and Sandstone hubs in Western Australia. The January 2026 updated Goldfields Hub Feasibility Study outlined production of more than 75,000oz per annum for six years, with financial metrics including approximately A$1 billion in life-of-mine cashflows, an A$606 million NPV8, and a 74% internal rate of return. Construction of the 1.5Mtpa processing plant is underway, with first gold production targeted for the June quarter of CY27.
For investors wanting to track the parallel development pathway at the company’s other Western Australian hub, our detailed coverage of the Goldfields project construction timeline walks through processing plant milestones, contractor appointments, and the capital schedule leading to first gold in the June quarter of CY27.
Ready to Explore the Bull Oak Deposit and Brightstar’s Sandstone Gold Project?
Brightstar Resources’ infill drilling at Bull Oak has returned some of the highest-grade assays in the company’s history, including a record 751g/t Au intercept, as the project advances toward a landmark Pre-Feasibility Study targeted for release before the end of 2026.
Investors tracking this emerging gold producer can explore Brightstar Resources’ full project profile and investment case on Discovery Alert to stay across upcoming resource updates, pending assay results, and the Sandstone PFS catalyst.