Resolution Minerals Ltd (ASX:RML, OTCQB:RLMLF, FRA:NC3) advanced its ambition to become an integrated US critical minerals supplier during the June 2026 quarter, securing federal permitting support, launching a major drilling campaign and demonstrating strong metallurgical outcomes across its Horse Heaven Project in Idaho.
The quarter was marked by FAST-41 Transparency Coverage for the Antimony Ridge Project, progress toward a second FAST-41 designation for Golden Gate, the start of up to 13,700 metres of diamond drilling and the completion of a strongly supported A$20 million institutional placement.
Resolution also strengthened its engagement with the US critical minerals and defence sectors, with the company admitted to the US Defense Industrial Base Consortium after quarter-end.
The company held A$10.34 million in cash and cash equivalents at June 30, with the second tranche of its placement expected to further support drilling, metallurgy, permitting and potential downstream processing initiatives.
Horse Heaven positioned as integrated US critical minerals platform
Resolution’s primary focus was its 100%-owned Horse Heaven Project, which includes the Antimony Ridge antimony-silver system, the Golden Gate gold-tungsten targets and the Johnson Creek processing site and historical tungsten stockpiles.
The project is immediately adjacent to Perpetua Resources’ permitted Stibnite Gold Project and is being advanced as a potential domestic source of antimony, tungsten and gold.
Resolution said increasing geopolitical concern over the security of critical mineral supply chains, particularly following restrictions on Chinese antimony and tungsten exports, reinforced Horse Heaven’s strategic importance.
Antimony and tungsten are both recognised by the US Government as critical minerals due to their use in defence, energy and industrial applications.
FAST-41 status supports accelerated permitting
Antimony Ridge was granted FAST-41 Transparency Coverage by the US Federal Permitting Council during the quarter, recognising its potential importance as a domestic antimony source.
The designation is expected to improve coordination between federal agencies and support permitting applications covering large-scale bulk sampling and drilling programs of up to 250 holes.
After the end of the quarter, Golden Gate also received FAST-41 Transparency Coverage, giving Resolution two projects operating under the federal framework.
The company said the designations should enhance permitting transparency, increase investor visibility and support engagement with strategic partners and potential funding sources aligned with US critical minerals policy.
Resolution’s subsequent admission to the Defense Industrial Base Consortium provides another avenue for collaboration with government agencies and access to defence-related supply chain and funding initiatives.
Large antimony-silver system emerges at Antimony Ridge
Three-dimensional modelling at Antimony Ridge identified more than 100 antimony-bearing veins represented by about 30 mineralised vein swarms, fault breccias and stockwork zones.
The mineralised system extends across an area of around 1,000 metres by 700 metres and more than 250 metres vertically, remaining open in all directions.
Historical mining and recent fieldwork indicate that the high-grade veins may be surrounded by a broader halo of lower-grade antimony mineralisation, adding to the project’s scale potential.
Sampling has returned antimony values ranging from 31.7% to 48.7%, along with silver grades of up to 1,420 grams per tonne.
Resolution said the results supported its view that Antimony Ridge is among the highest-grade antimony systems being advanced by an ASX-listed company.
Metallurgy supports downstream processing potential
Resolution achieved an important metallurgical milestone by producing an intermediate antimony trioxide product grading 99.38% Sb₂O₃ from historical stibnite material sourced from Antimony Ridge.
The product was generated using conventional pyrometallurgical processing methods, providing support for further studies into a potential domestic US processing pathway.
Additional flotation work returned sulphide recoveries of up to 99.5%, indicating near-complete recovery of stibnite from lower-grade material containing about 10% antimony.
Cleaner flotation work is continuing with the aim of increasing concentrate grades toward commercial specifications, while hydrometallurgical testing is underway at ANSTO.
Resolution believes the lack of modern antimony processing infrastructure in the US creates an opportunity for the company to participate further downstream in the supply chain.
Its ownership of the Johnson Creek site, including access to power, water, roads and private land, could provide infrastructure options for future processing.
Tungsten stockpiles deliver strong concentration results
Preliminary gravity separation testwork on historical stockpiles at Johnson Creek produced tungsten concentrates grading up to 52.3% WO₃.
Recoveries reached 75.5%, representing a 19-fold upgrade from the original stockpile grade of 1.85% WO₃.
Historical tungsten-bearing material is stored at the Johnson Creek site and near the portal of the former Golden Gate Tungsten Mine.
Resolution is evaluating whether these stockpiles could support a potential near-term processing opportunity and contribute to its broader integrated critical minerals strategy.
Major Golden Gate drilling campaign advances
Resolution commenced its Phase 2 diamond drilling program at Golden Gate during the quarter, with up to 45 holes and 13,700 metres planned.
Two drill rigs were mobilised, with about half of the planned program completed after quarter-end.
The campaign is designed to define the scale and extent of gold and tungsten mineralisation, test extensions to known mineralised zones and advance Golden Gate toward a maiden Mineral Resource Estimate.
Initial drilling encountered sulphide mineralisation, alteration, shearing, brecciation and veining in all holes completed at the time of reporting.
These features were considered comparable to geological characteristics associated with previously identified mineralisation at Golden Gate North and South.
Post-quarter reporting showed 16 diamond holes had been completed for about 4,470 metres of drilling, at an average depth of approximately 279 metres.
Gold recoveries strengthen development case
Preliminary metallurgical testing on Golden Gate drill core returned strong recoveries from both oxide and sulphide material.
Conventional cyanide leaching of oxide samples achieved gold recoveries of 94.2% at a 150-micron grind and 95.5% at 75 microns.
Sulphide flotation testing returned gold recovery of 86.4% at 106 microns, producing a concentrate grading about 49 g/t gold, while recovery increased to 88.7% at a finer 75-micron grind.
Resolution said the results indicated that both mineralisation types could be amenable to conventional processing methods, reducing technical risk as the project progresses toward resource definition and future economic studies.
Institutional support funds accelerated work
Resolution raised approximately A$20 million before costs through an institutional placement priced at A$0.07 per share.
The placement was cornerstoned by Tribeca Investment Partners and L1 Capital Global Opportunities Master Fund and was completed at a premium of about 6.3% to the company’s 20-day volume-weighted average price.
Funds are being directed toward Golden Gate drilling, antimony, tungsten and gold metallurgy, FAST-41 permitting activities and the assessment of downstream processing opportunities.
The board was also strengthened through the planned appointment of international mining executive Brett Lynch as a non-executive director ahead of Resolution’s proposed Nasdaq listing.
Next steps
Resolution plans to continue the Golden Gate drill campaign during the September quarter and receive initial assay results from submitted core.
Work will also focus on testing gold and tungsten extensions, progressing FAST-41 permitting at Antimony Ridge and refining the geological model for the broader antimony-silver system.
Further antimony flotation and hydrometallurgical results are expected, alongside additional evaluation of tungsten stockpile processing and potential use of the Johnson Creek infrastructure.
The company will continue engaging with US Government agencies, strategic stakeholders and Defense Industrial Base Consortium programs as it advances Horse Heaven toward an integrated domestic critical minerals operation.