Resolution Minerals (ASX:RML) Expands Antimony Ridge Footprint with High-Grade Sampling Results

Highlights

• Rockchip sampling at the Antimony Ridge target returned up to 49.8% Sb, 1,420 g/t Ag, and 4.43 g/t Au, the highest grades recorded at Horse Heaven to date.
• Soil sampling defined a 1,000m x 700m mineralised corridor, revealing a footprint significantly larger than previously recognised and open-ended along strike.
• Historical drilling confirmed significant gold intersections but was not assayed for antimony and only partially for silver.
• Follow-up work will include further rockchip sampling, bulk sampling and mapping at Antimony Ridge.
• At the Golden Gate target, six core drill holes (4,967 feet) have been completed, with assays from the first two holes submitted for assaying.

Resolution Minerals Ltd (ASX:RML) (OTCQB:RLMLF) has reported outstanding assay results from the recently completed surface rockchip and soil sampling program at the Antimony Ridge Target within the Horse Heaven Gold-Antimony-Tungsten Project in Idaho, USA.

The company has been conducting surface sampling programs at the Antimony Ridge and Golden Gate targets, aimed at defining a possible Sb-Au-Ag JORC-compliant Exploration Target while verifying historical exploration and production data.

Outstanding Rockchip Sampling Results at Antimony Ridge

Rock samples comprising massive stibnite were collected from a historical antimony mine at Antimony Ridge as part of a historical data verification program.

Peak rockchip results included grab sample 730253, which returned 49.8% Sb, 1,420 g/t Ag and 3.12 g/t Au, marking the highest grades recorded at Horse Heaven to date. Another grab sample, 730255, reported 10.35% Sb, 68.5 g/t Ag and 4.43 g/t Au. These results improve understanding of antimony mineralisation grades historically considered to be of economic importance and will support the integration of historical production data into future JORC-compliant exploration targets and resource estimates.

Expanded Mineralised Zone Defined by Soil Sampling at Antimony Ridge

The soil sampling program included 210 samples collected on a NE-SW grid (100m line spacing, 25m sample spacing), returning assays for Au, Ag, Sb, and W. Soil sampling has helped define a NE-SW trending zone of Sb-Ag-Au mineralisation measuring 1,000m by 700m. Within this corridor, assays returned up to 0.5% Sb, 0.9 g/t Au and 68 g/t Ag from an area southwest of historical sampling.

Heat maps highlight significant Sb-Ag-Au anomalies aligned with en echelon structures, with several zones showing fault offsets. Importantly, this mineralised footprint remains open-ended along strike in both directions.

The new soil results reveal that the mineralised footprint is materially larger than previously recognised and suggest the possibility of additional parallel Sb-Ag-Au zones.

Historical Data Highlights Untapped Potentia

Prior trench rockchip results included assays up to 5.9 g/t Au, 19% Sb and 367 g/t Ag, located centrally within this expanded zone. Mineralisation is exposed at surface along 500m of historical trenching, where small-scale antimony production was recorded during WWII and into the early 1950s.

Historical drilling at Antimony Ridge reported intersections of significant gold mineralisation, including 1.0 g/t Au over 36.8m in hole GGR-12 and 0.79 g/t Au over 19.8m in hole GGR-16. However, these drillholes were not assayed for antimony and only partially assayed for silver, leaving significant potential untested.

Planned Exploration and Metallurgical Work

Resolution Minerals plans to continue follow-up work at Antimony Ridge, including additional rockchip sampling, mapping, and bulk sampling to refine drill targets for a later program. Representative samples of stibnite-silica vein exposures are being collected for preliminary metallurgical test work.

Drilling Progress at Golden Gate Target

As part of the ongoing Phase 1 drill program, the company has also completed six core drill holes at the Golden Gate target, totalling 4,967 feet (1,513m), and is currently drilling its seventh hole. The first two holes have been logged, split, and submitted for assay, with results to be released once available.

RML Shares Rally

RML shares were trading 10.41% higher at AUD 0.053 per share at the time of writing on 15 September 2025.