RMX in hot pursuit of antimony with new project, pushing into Idaho’s famed Stibnite Mining District

• Red Mountain Mining acquires Yellow Pine antimony project in Idaho’s Stibnite Mining District
• The project sits just 2km from Perpetua Resources’ Stibnite project with 148Mlb in antimony reserves
• Initial exploration of mapping and sampling is aimed at finding evidence of mineralisation for drill testing

Special Report: Red Mountain Mining is doubling down on its pursuit of the red-hot critical metal antimony with the acquisition of the highly prospective Yellow Pine project in Idaho’s historical Stibnite Mining District.

The Stibnite Mining District was a major source of antimony in the first half of the 20th Century with recorded production of 39,930t from the Yellow Pine and Hangar Flats deposits between 1932 and 1952.

While the historical production is certainly encouraging, Yellow Pine’s real attraction is being within just 2km of Perpetua Resources’ Stibnite gold-antimony project that has a contained proved and probable reserve of 4.8Moz gold and 148Mlb antimony.

Highlighting the level of interest the US Government has in antimony, which has a range of defence applications, the Stibnite project has received $80m in Department of Defense funding and recently secured development approval under the FAST-41 approvals fast-track program.

Red Mountain Mining (ASX:RMX) will also have fellow Australian Resolution Mining (ASX:RML) for company as the latter’s Horse Heaven antimony project is immediately west of Perpetua’s claims and 5km north of the company’s project area.

The acquisition of Yellow Pine follows closely on the acquisition of the Utah antimony project earlier this month.

Both projects are expected to benefit from the Trump administration’s focus on securing critical mineral supply chains with recent discussions mentioning a potential federal fund to provide up to US$5bn in support.

Yellow Pine project

Mineralisation in the Stibnite District is controlled by regional faults and splays, and occurs within both the Idaho Batholith and surrounding older sedimentary rocks.

The Yellow Pine project, which covers 29 claims across 242.46 hectares, contains all the necessary elements for the formation of economic gold-antimony mineralisation.

Geological mapping carried out by the Idaho Geological Survey in 2017 shows that Yellow Pine features similar prospective geology to that seen within the Perpetua’s Stibnite project area.

While there is no evidence of modern exploration activity within the claims, RMX’s geologists have successfully located the two eastern historical workings mapped by the Idaho Geological Survey.

These are small shallow pits that appear to be targeting brecciated quartz veins, likely seeking gold and/or antimony.

RMX’s initial exploration will consist of mapping and sampling targeting the main north-northeast-trending fault through the project area and the intrusive contact between the Idaho Batholith granites and the metasedimentary units.

This will seek to demonstrate evidence of hydrothermal fluid flow, brecciation, alteration and antimony-gold mineralisation, which will then be targeted for drill testing.

This article was developed in collaboration with Red Mountain Mining, 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.