Brightstar Resources Ltd
Brightstar Resources Sandstone Gold Resource Grows to 2.9Moz as Group Inventory Reaches 4.5Moz
Brightstar Resources (ASX: BTR) has reported a 113% increase in Measured and Indicated Mineral Resources at its Sandstone Gold Project, with the Brightstar Resources Sandstone gold resource grows to 2.9Moz following the latest Mineral Resource Estimate (MRE) update. The total Sandstone MRE now stands at 69Mt at 1.3 g/t gold for 2.9 million ounces. At the group level, the update takes Brightstar's consolidated resource base to 100Mt at 1.4 g/t gold for 4.5 million ounces, representing a tenfold increase in approximately three and a half years.
According to the announcement, the upgrade marks delivery of the first milestone under Brightstar's Two-Year Strategic Plan to Unlock Sandstone. A Pre-Feasibility Study (PFS), maiden Ore Reserve, and a second growth-focused MRE update are all targeted for the December quarter of CY26.
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The Numbers That Matter: A Resource Base Under Transformation
The headline figures from this interim MRE update reflect both scale and a marked improvement in geological confidence, according to the company.
Sandstone Gold Project, interim MRE (15 July 2026)
| Classification | Tonnes (Mt) | Grade (g/t Au) | Ounces (Moz) |
|---|---|---|---|
| Indicated | 24.7 | 1.5 | 1.1 |
| Inferred | 44.7 | 1.2 | 1.7 |
| Total | 69.3 | 1.3 | 2.9 |
The Indicated category carries particular weight in this update. A 113% increase to 1.1 million ounces at 1.5 g/t gold reflects the direct output of infill drilling campaigns across the project's key deposits, according to Brightstar. This higher-confidence classification is intended to underpin the forthcoming PFS and, ultimately, support a maiden Ore Reserve.
Brightstar group MRE, year-on-year growth
| Date | M&I (Moz) | Inferred (Moz) | Total (Moz) |
|---|---|---|---|
| Jun-22 | 0.2 | 0.3 | 0.5 |
| Jun-23 | 0.5 | 0.5 | 1.0 |
| Jun-24 | 0.7 | 0.8 | 1.5 |
| Jun-25 | 1.1 | 0.8 | 1.9 |
| Jul-26 | 1.9 | 2.6 | 4.5 |
Brightstar's group resource has grown from 0.5 million ounces in mid-2022 to 4.5 million ounces as at July 2026, a trajectory the company attributes to merger and acquisition activity across its Goldfields and Sandstone hubs combined with systematic drilling programmes.
Quality Over Quantity: The Strategy Behind the Update
Brightstar has stated that this update was structured to prioritise improved geological confidence and resource classification ahead of raw ounce growth. The company applied tighter geological controls, reinterpreted mineralised domains, and used its own estimation parameters across these deposits for the first time.
Furthermore, the interim MRE captures drilling completed prior to May 2026 only. With four rigs currently active at Sandstone, a substantial volume of additional drilling remains to be incorporated into future updates.
Managing Director Alex Rovira commented: "The result has exceeded expectations for Mineral Resource growth in this first update, with the strategic focus to date on improving the quality of the Mineral Resource ahead of the PFS and eventual mining development. Importantly, the project now hosts 1.1Moz of Indicated-classified Mineral Resources. This higher confidence is crucial for the delivery of our PFS, and we are targeting further increases in subsequent estimates with drilling underway now at key deposits such as Bull Oak, Indomitable and Two Mile Hill-Shillington."
Standout Deposit Growth: Where the Ounces Originated
Several individual deposit upgrades stand out for their scale within the broader Sandstone update.
Key deposit MRE changes
| Deposit | New MRE | Previous MRE | Change |
|---|---|---|---|
| Bull Oak | 10.5Mt at 1.0 g/t for 322koz | 2.5Mt at 1.1 g/t for approximately 90koz | +258% |
| Achilles / Airport | 6.4Mt at 1.1 g/t for 224koz | 2.1Mt at 1.5 g/t for approximately 99koz | +126% |
| Indomitable Camp | 10.9Mt at 1.0 g/t for 366koz | 8.2Mt at 1.1 g/t for approximately 296koz | +24% |
| Two Mile Hill / Shillington | 14.6Mt at 1.6 g/t for 731koz | 14.9Mt at 1.6 g/t for approximately 755koz | Restated at lower cut-off |
Bull Oak recorded the largest percentage increase, with contained ounces rising by 258% from approximately 90,000 ounces to 322,000 ounces. According to Brightstar, the deposit remains open along strike and at depth, indicating further resource growth may be possible as additional drilling data is incorporated.
Achilles also registered a 126% resource increase and, per the company, remains open for further extension.
Understanding Mineral Resource Classification
For investors less familiar with resource reporting terminology, the distinction between Indicated and Inferred resources is central to interpreting this update's significance.
JORC resource classification, a simple guide
| Classification | What it means | Why it matters |
|---|---|---|
| Measured | Highest confidence; drill spacing tight enough for detailed mine planning | Can convert directly to Ore Reserves |
| Indicated | Reasonable geological confidence; sufficient for PFS-level mine planning | Forms the basis of feasibility studies and project financing |
| Inferred | Lower confidence; geological continuity assumed but not fully demonstrated | Cannot be used in Ore Reserve estimates; requires further drilling |
The key distinction is that Ore Reserves — the figures underpinning mine plans and production decisions — can only be derived from Measured and Indicated resources. The 113% growth in the Indicated category at Sandstone is therefore positioned by the company as a direct enabler of the forthcoming PFS and maiden Ore Reserve, rather than simply a resource size milestone.
The Conversion Pipeline: Over 1.0Moz of Inferred Resources Targeted
This interim update captures only a portion of drilling completed at Sandstone to date. Three deposits currently hold more than 1.0 million ounces combined in the Inferred category and are the focus of ongoing conversion drilling:
- Two Mile Hill-Shillington: 541,000 ounces Inferred, with infill drilling ongoing
- Indomitable Camp: 284,000 ounces Inferred, with infill drilling targeted for completion in August 2026
- Bull Oak: 278,000 ounces Inferred, with infill drilling targeted for completion in August 2026
Following completion of infill programmes at Indomitable and Bull Oak, Brightstar's exploration strategy is set to pivot toward growth-focused exploration, targeting new discoveries across the broader Sandstone district, according to the company.
Approximately 40% of the 146,000 metres of drilling completed since Brightstar acquired the Sandstone Project has yet to be incorporated into any MRE. The company has indicated the second update, due alongside the PFS in the December quarter of CY26, has potential to deliver further resource growth.
Key Milestones Through the Remainder of 2026
Brightstar has outlined an execution roadmap for Sandstone covering the balance of the calendar year.
| Milestone | Expected timing |
|---|---|
| Infill drilling completion at Indomitable and Bull Oak | August 2026 |
| Pivot to growth-focused exploration drilling | Post-August 2026 |
| Second growth-focused Sandstone MRE update | Q4 CY26 |
| Sandstone Pre-Feasibility Study release | December quarter CY26 |
| Sandstone maiden Ore Reserve | December quarter CY26 |
Separately, Brightstar continues to advance its Goldfields Hub, where a January 2026 updated Feasibility Study outlined production of more than 75,000 ounces per annum for six years, with life-of-mine cashflows of approximately $1 billion, an $606 million net present value at an 8% discount rate, and a 74% internal rate of return, according to the company.
Construction of the 1.5 million tonne per annum processing plant is underway, with gold production targeted to commence in the June quarter of CY27.
What This Means for Investors
Brightstar's Sandstone update forms part of a broader gold resource base spanning Western Australia's Goldfields and Sandstone regions. Several factors from the announcement are relevant to how the update may be interpreted by the market.
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Scale: A 4.5 million ounce group resource base places Brightstar among a group of ASX-listed companies with substantial undeveloped gold inventories in Western Australia.
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Resource quality focus: The deliberate emphasis on converting Inferred to Indicated resources, evidenced by the 113% M&I increase at Sandstone, reflects a stated approach to managing project risk ahead of development decisions.
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Production timeline: The Goldfields Hub is under construction, with first gold targeted for mid-2027 according to company guidance, which management has indicated could support ongoing Sandstone development activity.
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Active drilling programmes: With four rigs currently active at Sandstone and infill programmes targeted for completion in August, a PFS, maiden Ore Reserve, and second MRE update are all anticipated before year end.
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Infrastructure position: Sandstone assets are located near sealed highways on granted mining leases, with conventional open-pit mining methods proposed and historical metallurgical recoveries of 85% to 98% via carbon-in-leach (CIL) processing, according to test work referenced in the announcement.
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Glossary of Key Terms
Mineral Resource Estimate (MRE): A JORC-compliant estimate of the quantity and grade of mineralisation considered to have reasonable prospects for economic extraction.
JORC Code: The Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves, the industry standard for resource reporting in Australia.
Indicated Resource: A resource estimated with sufficient geological confidence to support mine planning at the PFS stage; can be used in Ore Reserve calculations.
Inferred Resource: A lower-confidence estimate where geological continuity is assumed rather than confirmed; cannot be used in Ore Reserve estimates.
Ore Reserve: The economically mineable portion of a Measured or Indicated Mineral Resource, incorporating mining, metallurgical, and economic factors.
Pre-Feasibility Study (PFS): A study evaluating the technical and economic viability of a project in sufficient detail to support a decision to proceed to further feasibility work or an investment decision.
Carbon-in-Leach (CIL) Processing: A conventional gold processing method involving cyanide leaching and carbon adsorption, widely used across Western Australia.
Cut-off Grade: The minimum ore grade at which material is considered economic to mine. Brightstar has applied a 0.4 g/t gold cut-off to most Sandstone deposits, reflecting current gold price assumptions and open-pit mining parameters.
Key takeaway: The Brightstar Resources Sandstone gold resource grows to 2.9Moz alongside a group resource base of 4.5 million ounces, with a PFS, maiden Ore Reserve, and second MRE update all targeted for the December quarter of CY26. With drilling ongoing at four rigs, further updates to the resource base are anticipated as additional data is incorporated.
Want to Learn More About Brightstar Resources and Its Growing Gold Portfolio?
With a 4.5 million ounce group resource base, a Pre-Feasibility Study on the horizon, and construction already underway at its Goldfields Hub, Brightstar Resources (ASX: BTR) is advancing on multiple fronts simultaneously. Investors seeking to understand the full scope of the Sandstone Gold Project, the Goldfields Hub development timeline, and Brightstar's broader strategy for unlocking value across its Western Australian portfolio can find further information by visiting the company's official website at brightstarresources.com.au.
