Resolution Minerals Ltd: Antimony Ridge Model Shows Extensive Antimony Vein Swarms

Adelaide, Australia - Resolution Minerals Ltd. (ASX:RML) (FRA:NC3) (OTCMKTS:RLMLF) reported that results of recent 3D modelling of the numerous Antimony and Silver-bearing veins and vein swarms that are exposed over a large area (1000m x 700m) in past mining pits, reveals the potential for a significant size Antimony-Silver deposit at Antimony Ridge, with an open-ended target and expanding scale potential.

HIGHLIGHTS

3D Modelling: Three-dimensional ("3D") modelling of numerous known Antimony and Silver bearing veins, veins swarms and stockworks, over a large area (1000m x 700m), reveals significant size and expanding scale potential at the Antimony Ridge Mine Project ("Antimony Ridge"), within Resolution's Horse Heaven Antimony-Tungsten-Gold-Silver Project ("Horse Heaven").

High Grades, Historical Mining: The Antimony-Silver-bearing veins, mined historically during World War I &II and the Korean War, have returned exceptionally high-grade Antimony (Sb) consistently above 30% up to 50% Sb and Silver (Ag) grades above 250 g/t Ag up to 1,420 g/t Ag (ASX announcement 15 September 2025).

Numerous Vein Swarms: 3D modelling and ground mapping has identified more than 100 highgrade veins, modelled as 30 mineralised vein swarms, fault breccias and stockworks.

Large Area: 3D modelling demonstrates that the mineralised vein swarms are arranged in en echelon clusters extending over a large area of approximately 1,000m x 700m (170 acres) and have a vertical range of 250m as indicated in outcrop elevations.

Large Lower Grade Halo: Prior rock chip and soil sampling results show that the high-grade en echelon vein swarms occur within a broader zone of lower grade veinlets and stockworks with 0.5% to 2% Sb.

Metallurgy Results Soon: Preliminary metallurgy test results are in process over a 100kg mini bulk-sample collected of representative high-grade stibnite material.

FAST-41: Horse Heaven was selected for the U.S. FAST-41 Transparency Coverage by the US-based Permitting Council, expected to accelerate permitting timelines with an application for 250 drill holes and large-scale bulk sampling (ASX announcement: 8 April 2026).

Antimony Ridge forms part of Resolution's broader Horse Heaven strategy, which includes recently acquired processing infrastructure, tungsten stockpiles and a major 2026 drilling program at Golden Gate starting in May.

This result follows the selection of Antimony Ridge for FAST-41 Transparency Coverage from the US Permitting Council, announced on 8 April 2026. Selection reflects the strategic importance of Antimony Ridge as a potential source of U.S. domestic antimony supply, a critical metal essential for defence, energy, and industrial applications.

Antimony Ridge is located within Resolution's Horse Heaven Antimony-Tungsten-Gold-Silver Project in Idaho, USA, and immediately adjacent to Perpetua Resources' Stibnite Gold Project, a large, recently permitted Antimony-Gold project.

Craig Lindsay, CEO of US Operations, stated: "Antimony Ridge hosts an Antimony-Silver vein and vein swarm system comprising high grade large veins, stacked "en echelon", within a broader system of mineralised stockworks with a total strike length of 1,000m, open-ended in all directions.

Such is the consistency of the vein frequency, and the vein swarms, that there is a high probability that future work will uncover more veins and extend the length and width of the vein system.

The modelling has revealed significant size potential which demonstrates the strategic importance of Antimony Ridge as a potential source of U.S. domestic antimony supply."

Historical Mining at Antimony Ridge by the US Government as Key Antimony Source for US Military Historical mining occurred at Antimony Ridge by the US Government during World War I, WWII and the Korean War. During World War II, the local District, including the adjoining Stibnite mine (Perpetua Resources), is estimated to have produced more than 90% of the US Antimony (Source: Perpetua Resources Stibnite Feasibility Study, Jan 2021). Antimony Ridge was a key source of Antimony for the US military.

Ore was processed offsite at third party mills. As a result, other than underground adits and surface open pits and trenches, there are no environmental liabilities requiring clean-up.

Mapping and Sampling Identifies Mineralised Vein Swarms, Fault Breccias and Stockworks Over a Large Area.

More than 100 high-grade stibnite veins, vein swarms, fault breccias and stockworks have been defined in several phases of detailed mapping and sampling at Antimony Ridge (see Figure 5*). The stibnite vein frequency is high and some veins are quite long, over 100m in length.Open-ended vein swarms have been mapped extending off the ridgeline from the past open pits.

Detailed 3D analysis and modelling of mapping data have led to the recognition of 30 discrete zones of SbAg veins, vein swarms, fault breccias and stockworks.

3D modelling also demonstrates that the mineralised vein swarms are arranged in en echelon clusters extending over a large area of approximately 1,000mx 700m (170 acres) and have a vertical range of 250m (as indicated in outcrop elevations) and are exposed in past open pits and in more recent trenches.

Each discrete zone of Sb-Ag veins is up to 100m in strike length with the highest grade veins up the 1m thick (true thickness). More mineralised zones and clusters are expected to be defined as exploration in all direction is incomplete.

Assays Support High-Grade Antimony - Silver Grades in Stibnite Veins in Prior Open Pits Assays and sample product support the high-grade Antimony veins and vein swarms with results from two independent labs (ALS, KPM). Exceptional high-grade Antimony and Silver results were returned from a large volume rock sampling program within the prior open pits of Antimony Ridge. Antimony grades varied from 31.7% Sb to 48.7% Sb from five (5) large rock samples, with grades averaging 39.2% Sb, 430 g/t Ag and 0.92 g/t Au. These large volume samples confirmed the presence of exceptionally high-grade mineralisation. All rock samples, which are significantly larger than rock chip samples and having an average weight of 3.6 kg per sample (ASX announcement 14 January 2026, 24 September 2025).

Large Lower-grade Antimony Halo surrounds High-Grade Stibnite Veins and Vein Swarm Clusters A large lower grade Antimony-Silver halo surrounds the higher-grade stibnite veins and vein swarm clusters. Comprising zones of veinlets and stockworks, the Antimony-Silver halo has a grade consistently between 0.5%Sb to 2% Sb, 5 g/t Ag to 60 g/t Ag within a broad Antimony-Gold-Silver soil geochemical footprint (ASX announcement 24 September 2025).

Antimony-Gold-Silver soil geochemical anomalies represented a series of mineralised NE-SW zones that sub-parallel the main trend of mineralised en-echelon structures that traverse Antimony Ridge. These repeated (or "stacked") NE-SW vein swarms, clusters and mineralised zones form a broad corridor of mineralisation approximately 1,000m long and 700m wide (170 acres).

Thirty-six (36) rockchip samples (channel and grab) were collected in the 2022-2023 program with results averaging 0.7-1.9 % Sb, 31-60 g/t Ag and 1.9 g/t Au, with peak values of 19% Sb, 367g/t Ag and 5.9g/t Au (ASX announcements 11 June 2025 and 24 September 2025).

Initial Metallurgy Test Results to be released soon

Initial metallurgy test results are in process and expected to be released soon from two different processing options, based on ~100kg of samples collected of representative high-grade stibnite material. The samples were submitted to Kingston Process Metallurgy Inc. (Kingston, Ontario, Canada) for pyrometallurgical flowsheet validation, ANSTO Minerals (Sydney, NSW, Australia) for hydrometallurgical flowsheet validation and Independent Metallurgical Operations Pty Ltd (Perth, WA, Australia) for preliminary mineral processing metallurgical test work and mineralogical characterisation studies.

An end-product of antimony trioxide is expected soon for pre-qualification with potential US end users.

Fast-41 Transparency Coverage Project

The Antimony Ridge Mine Project is a high-priority development project for antimony, a key critical mineral, located in a friendly, tier-one jurisdiction in the centre of Idaho, USA. Antimony Ridge was recently selected for the U.S. FAST-41 Transparency Coverage by the US-based Permitting Council which is expected to accelerate permitting timelines (ASX announcement 8 April 2026).

Future Plans

Resolution plans to commence a significant bulk sampling program of high-grade Antimony ore and conduct an extensive drilling program up to 250 drill holes, once a Plan of Operations is approved (ASX announcement 8 April 2026).

Antimony Ridge is expected to be a cornerstone of Resolution's strategy to supply critical metals, including Antimony, Tungsten and Gold, from central Idaho in the USA.

Resolution is initiating a major Phase 2 drilling program in May 2026, at the Golden Gate Project, located within the Company's larger Horse Heaven Antimony-Tungsten-Gold-Silver Project. The program comprises up to 45,000 ft (13,700 metres) of diamond core drilling across up to 45 holes and represents a substantial expansion of the Company's successful 2025 drilling campaign at Golden Gate, where all holes intersected gold mineralisation and remain open at depth. Drilling is designed to define the scale of gold and tungsten mineralisation at Golden Gate and Golden Gate South and support progression toward a maiden Mineral Resource Estimate. Importantly, FAST-41 selection supports Resolution's broader strategy to develop a U.S.-focused critical mineral platform. Antimony Ridge is one of several advancing components within Horse Heaven Project.

Antimony Ridge is expected to be a cornerstone of Resolution's strategy to supply critical metals, including Antimony, Tungsten and Gold, from central Idaho in the USA.

*To view tables and figures, please visit:
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About Resolution Minerals Ltd:

Resolution Minerals Ltd (ASX:RML) (OTCMKTS:RLMLF) (FRA:NC3) is a mineral exploration company engaged in the acquisition, exploration and development of precious and battery metals - such as antimony, gold, copper, and uranium.

Resolution Minerals Ltd Listed on the ASX in 2017 and has a broad portfolio of assets, such as the Drake East Antimony-Gold Project in north-eastern NSW and George Project prospective for silica sand and uranium.

Source:
Resolution Minerals Ltd

Contact:

Aharon Zaetz Executive Director Resolution Minerals Ltd M: +61 424 743 098 ari@resolutionminerals.com Jane Morgan Investor Relations Jane Morgan Management M: +61 405 555 618 jm@janemorganmanagement.com.au