The 19-hole program totalling 2971m at the Iris deposit returned results such as:

  • 4m grading 21.3g/t gold from a down-hole depth of 91m including 2m at 37.9g/t as well as 2m at 12.8g/t from 120m including 1m at 24.4g/t (MDRC983);
  • 21m at 1.59g/t Au from 148m including 1m at 13.5g/t from 166m (MDRC980); and
  • 3m at 2.17g/t Au from 45m, 5m at 5.73g/t from 99m and 15m at 1.22g/t from 110m (MDRC971).

Notably for Astral Resources (ASX:AAR), the very high-grades in MDRC983 are outside the pre-feasibility study pit designs, which indicates potential for additional high-grade feed for the proposed Mandilla process plant.

The two lines of drilling at Iris followed up successful infill drilling reported in December 2024 and increased the infilled area at a 40m by 20m drill spacing to 140m by 360m.

“This is the second phase of infill drilling at Iris, with the strong results likely to support a further increase in indicated mineral resources when we deliver our next update to the Mandilla resource estimate planned for the March quarter of 2026,” managing director Marc Ducler said.

“The higher-grade core of the deposit has again delivered strong results, including 23 metres at 1.00g/t Au from 156m and 21 metres at 1.59g/t Au from 148m.

“Additionally, MDRC983 returned two very high-grade intersections outside of the current pre-feasibility mine design, including 4 metres at 21.3g/t Au from 91m and 2 metres at 12.8g/t Au from 120m.

“These high-grade results will complement the next resource update at Iris, with further drilling to the south currently being planned.”

The company’s flagship Mandilla project sits in the northern Widgiemooltha greenstone belt, about 70km south of Kalgoorlie, WA.

The area hosts world-class deposits such as the Golden Mile Super Pit, Gold Fields’ St Ives gold mine and Westgold Resources (ASX:WGX) Beta Hunt gold mine.

Mandilla is no slouch as it hosts a resource of 42Mt grading 1.1g/t, or 1.43Moz of contained gold, within the Theia, Iris, Eos and Hestia deposits. About 63% of the resource is in the indicated category that has enough geological certainty for mine planning.

Metallurgical testing undertaken on each of the main deposits has demonstrated high gravity recoverable gold, fast leach kinetics and exceptional overall gold recoveries of up to 99.5% with low reagent consumptions and coarse grinding.

A pre-feasibility study released in June 2025 envisioned a standalone project with seven open pit mines (four at Mandilla and three at Feysville) feeding a 2.75Mtpa processing facility to produce 95,000ozpa gold in the first 12 years.

Using a conservative Australian gold price of $4250/oz, this is expected to deliver net present value – a measure of a project’s profitability – of $1.4bn at an 8% discount rate.

AAR noted the latest drill results targeting the inferred higher grade “core” of the Iris deposit provided further confidence that this zone of mineralisation was likely to support conversion into the higher confidence indicated category.

At Hestia deposit, a 24-hole reverse circulation program carried out to sterilise the south waste rock landform location and test for an extension to an offset lode returned a best assay of 4m at 2.08g/t gold from 192m (MDRC998).

This was 40m south of the known extent of gold mineralisation at Hestia and is likely an extension of the main gold mineralised trend.

Holes drilled south of the known extent of Hestia mineralisation did not encounter significant mineralisation and the program is considered to have been successful in sterilising the proposed waste landform footprint to the south.