Brightstar Resources Boosts Sandstone Gold Resources to 2.9Moz with 113% Increase in Indicated Category

Sandstone Resource Expansion Sets Stage for Development

Brightstar Resources (ASX:BTR) has unveiled a significant upgrade to its Sandstone Gold Project, with the total Mineral Resource Estimate (MRE) climbing to 2.9 million ounces of gold. Notably, the Measured and Indicated categories, the higher-confidence resource classes that underpin mining studies, have more than doubled, reaching 1.1 million ounces at a grade of 1.5 grams per tonne. This marks a critical milestone as the company prepares to release its Pre-Feasibility Study (PFS) and maiden Ore Reserve later this year.

The 18% increase in total Sandstone resources is the product of extensive drilling campaigns completed throughout 2025 and into mid-2026, with four rigs currently active on site. Brightstar has focused on upgrading geological confidence rather than merely chasing headline growth, applying tighter geological controls and reinterpreting mineralised domains to deliver a more robust resource model. The company’s Managing Director, Alex Rovira, highlighted that this approach has yielded a more reliable foundation for near-term development plans.

Bull Oak and Achilles Drive Resource Growth

Among the standout contributors to the resource upgrade are the Bull Oak and Achilles deposits. Bull Oak’s resource has ballooned by 258% to 322,000 ounces at 1.0 g/t gold, while Achilles has grown 126% to 224,000 ounces at 1.1 g/t. Both remain open along strike and at depth, indicating further upside potential. The Indomitable Camp also saw a 24% increase to 366,000 ounces, reinforcing the pipeline of quality ounces within the Sandstone Hub.

Brightstar is actively drilling to convert over 1 million ounces currently classified as Inferred into the Indicated category ahead of the PFS. Key targets include Two Mile Hill-Shillington (541,000 ounces Inferred), Indomitable (284,000 ounces), and Bull Oak (278,000 ounces). This conversion is vital for de-risking the project and underpinning the upcoming Ore Reserve estimate.

Group Mineral Resources Multiply Tenfold in 3.5 Years

The Sandstone upgrade lifts Brightstar’s total group Mineral Resource to 4.5 million ounces at an average grade of 1.4 g/t gold, representing a tenfold increase since mid-2022. This growth has been driven by a disciplined combination of mergers and acquisitions and aggressive drilling across the Goldfields and Sandstone regions. The company is advancing its Goldfields Hub towards production, with a 1.5Mtpa processing plant under construction and first gold targeted in mid-2027.

Brightstar’s resource growth trajectory is underpinned by solid metallurgical fundamentals. Test work conducted by Independent Metallurgical Operations Pty Ltd and others shows gold recoveries ranging from 85% to over 98% using conventional carbon-in-leach processing. Importantly, deleterious elements such as arsenic and antimony are at low levels, reducing processing risks.

Strategic Focus on Resource Quality and Growth

Brightstar’s strategy has deliberately prioritised improving resource quality ahead of volume expansion, aiming to strengthen the confidence in its resource base. The updated MRE incorporates over 60% of the 146,000 metres drilled since Brightstar acquired the Sandstone Project in late 2024, applying rigorous geological interpretation and estimation parameters for the first time across many deposits.

Looking ahead, the company plans a second MRE update in the December quarter, coinciding with the Sandstone PFS release. This update will integrate ongoing drilling results, particularly from infill programs targeting key deposits. Following completion of these programs, exploration efforts will pivot towards growth-focused opportunities to further expand the resource base.

Brightstar holds granted mining leases across the Sandstone and Montague East projects, both located in Western Australia’s Tier-1 jurisdiction with good infrastructure access. The company’s focus on methodical resource development combined with advancing its Goldfields production hub positions it as a growing mid-tier gold producer in the region.