Brightstar Resources’ latest deep diamond drilling at Two Mile Hill within its Sandstone Gold Project has revealed a substantial mineralised tonalite unit with over 50 visible gold occurrences, suggesting significant potential for resource expansion.
- Over 50 visible gold occurrences in deep diamond drilling
- Mineralised tonalite unit up to 500m thick confirmed
- New Shirvington Zone extends mineralisation beyond 700m depth
- Two Mile Hill-Shillington resource currently 731koz at 1.6g/t Au
- Exploration targeting up to ten analogous felsic intrusives
Visible Gold Highlights Potential Resource Upside
Brightstar Resources Limited (ASX:BTR) has struck a rich vein of optimism with its first-ever diamond drill hole exceeding 1,000 metres at the Two Mile Hill deposit, part of the Sandstone Gold Project. The company reported intercepting more than 500 metres of mineralised tonalite hosting over 50 instances of visible gold, a striking indicator of a robust mineral system that could materially expand the current resource base.
The Two Mile Hill deposit, already part of a 2.9 million ounce resource at 1.3 grams per tonne gold, has revealed a tonalite intrusion far thicker and more extensive at depth than previously interpreted. The new drill holes, part of a four-hole, 3,400-metre program, have confirmed the tonalite unit now exceeds 300 metres in horizontal thickness and remains open below 700 metres, a zone Brightstar has dubbed the 'Shirvington Zone'.
Drilling Confirms Thick Mineralised Tonalite
The two completed diamond holes have each intersected wide intervals of mineralised tonalite ranging from 400 to 500 metres thick. Visible gold is predominantly associated with quartz veins containing sulphide minerals such as galena and pyrite, but notably, some gold is also embedded within the tonalite itself. The drilling extended beyond planned depths, ending in mineralised rock, reinforcing the potential for further extensions.
This discovery significantly expands the geological model for Two Mile Hill, where the combined Two Mile Hill-Shillington deposit currently holds 731,000 ounces at 1.6g/t Au. Brightstar’s Managing Director, Alex Rovira, described the visible gold intersections as "spectacular," underlining the scale and quality of the mineralised system and the excitement around the upcoming assay results expected in late September.
Strategic Exploration Targets Emerging
Beyond Two Mile Hill, Brightstar is setting its sights on up to ten other felsic intrusive units identified by geophysics near the deposit, which have never been systematically drilled. These targets, similar in nature to the tonalite-hosted mineralisation at Two Mile Hill, could represent multiple new mineralised systems within the Sandstone Greenstone Belt.
The company’s exploration strategy is evolving alongside its pre-feasibility study and development plans, aiming to unlock further value from these largely untapped felsic intrusives. The potential to replicate Two Mile Hill’s mineralisation style across these targets could transform the Sandstone project’s scale and longevity.
Ongoing Drilling and Resource Updates
The current drilling program, which has two holes remaining, aims to delineate the Shirvington Zone and better define the tonalite-hosted mineralisation at depth. The assays from previous infill drilling supporting the pre-feasibility study are also anticipated shortly, which will provide further clarity on grade continuity and resource confidence.
Brightstar’s broader portfolio includes over 4.5 million ounces of Mineral Resources across Western Australia’s Goldfields and Sandstone regions, with the Goldfields Hub targeting first production in mid-2027. The company is advancing rapidly toward becoming a mid-tier gold producer, with Sandstone’s resource growth complementing the near-term production focus at Goldfields. This recent drilling success adds a compelling chapter to Brightstar’s growth narrative, suggesting the Sandstone project’s resource base could be on the cusp of a meaningful upgrade.
Bottom Line?
Visible gold-rich thick tonalite at Two Mile Hill opens a promising chapter for Brightstar’s Sandstone resource growth, with assays and further drilling set to define the scale of the opportunity.
Questions in the middle?
- Will upcoming assay results confirm the high-grade potential suggested by visible gold?
- How will the Shirvington Zone extension impact the next Mineral Resource update and project economics?
- Can the exploration of analogous felsic intrusives replicate Two Mile Hill’s mineralisation success?