Brightstar supports mining goal at Yunndaga as drilling lands high-grade gold punches

• Diamond drilling at Yunndaga returns high-grade gold hits including 7m at 5.7g/t
• Brightstar targets Yunndaga as third underground mine with mining start in 2026
• Resource update due in weeks with maiden ore reserve declaration in coming months

Special Report: Brightstar Resources’ push to develop the Yunndaga deposit as its third underground gold mine has received a boost from diamond drilling returning high-grade hits.

Final assays from the diamond drilling at the Yunndaga deposit within its Menzies gold project in WA include:

• 7m grading 5.7g/t Au from a down-hole depth of 230m including 0.6m at 54.8g/t
  from 234.8m;
• 10.6m at 2.28g/t Au from 217m including 1.1m at 11.9g/t from 225.6m; and
• 4m at 2.51g/t Au from 262m including 1m at 8.45g/t from 265m.

Visible gold has also been observed in three separate diamond core holes.

The results complement recently reported reverse circulation drill assays such as 16m at 8.03g/t Au from 220m and 8m at 6.67g/t Au from 245m.

Brightstar Resources’ (ASX:BTR) drilling fulfilled the goals of infilling areas of the Yunndaga resource of 3.4Mt at 1.4g/t, or 156,000oz of contained gold, that fall within or adjacent to the optimised stope slopes released in the definitive feasibility study and to test for downdip extensions to known mineralisation.

It also fulfilled additional aims of providing further geotechnical and metallurgical information.

Previous mining studies highlighted the potential to mine high-grade portions of Yunndaga via underground mining methods, with the recent DFS highlighting a potential underground operation recovering ~60,000oz gold from the mining of 600,000t of ore grading 2.6g/t.

“These diamond drillhole results from Yunndaga mark the completion of another important phase of exploration activity at Menzies, with the RC and diamond drilling completed in order to facilitate the development of Yunndaga as Brightstar’s third underground mine targeted in CY2026,” managing director Alex Rovira said.

“The holes confirm the grades identified in the recent large-scale RC program and have supplied further sample material for Brightstar’s detailed metallurgical and geotechnical work to further de-risk this exciting underground development story.”

Yunndaga deposit

The Yunndaga deposit includes the historical mine of the same name that produced more than 270,000oz at an average grade of +16g/t – most of which came from the Princess Eva and Princess May underground workings.

Additional production was derived from later open pit mining with about 64,000oz at 2.5/t gold.

Current resources at the deposit extend to about 240m vertical depth with limited drilling below this.

BTR’s recently completed drill program was aimed at infilling the resource in areas optimised for underground mining, stepping out from the initial intercepts and testing for extensions at depth and to the north.

The diamond core component of the program also provided important geotechnical data and metallurgical sample material to help progress the development workstreams at the deposit.

Watch: Brightstar gains approval for open pit operations

Next steps

BTR is working on an update to the Yunndaga resource and will update the market in the coming weeks.

This will enable an updated mine design to be completed, which is expected to facilitate the declaration of a maiden ore reserve for Yunndaga in the coming months.

Project development activities continue for the start of mining at the Lady Shenton deposit in Menzies, with Brightstar aiming for this to occur in H1, 2026.

Exploration work is continuing across the company’s portfolio with Rovira noting that three surface rigs are drilling at the Sandstone Hub targeting material growth and improvements to the confidence classification of Sandstone’s 2.4Moz resource grading 1.5g/t.

“In Laverton, an underground diamond core rig is currently active at the Fish mine – targeting depth extensions to the ore body to provide mine life extensions, and an additional RC rig has just arrived at Lord Byron to follow-up on the exciting exploration results reported recently,” he added.

This article was developed in collaboration with Brightstar Resources, a Stockhead advertiser at the time of publishing.

This article does not constitute financial product advice. You should consider obtaining independent advice before making any financial decisions.