Red Mountain Mining flags high-grade antimony at Armidale Project amid record market prices

Red Mountain Mining Limited is generating renewed interest in Australia‘s critical minerals space following confirmation of high-grade antimony at its Armidale Antimony-Gold Project in New South Wales. A rock chip sample taken from the Oaky Creek historical workings returned an assay of 19.5% antimony—an unusually high grade indicating significant mineralisation potential. The sample, described as a massive stibnite vein with brecciated siliceous gangue, forms the cornerstone of a project that may soon evolve from forgotten historic ground into a key player in Australia’s critical minerals strategy.

This unexpected but promising result comes at a time when antimony prices are climbing to record highs, recently exceeding US$58,000 per tonne. Red Mountain’s Armidale project, situated in a region with sparse historical exploration and limited modern sampling, now offers both geological and strategic upside as markets pivot toward securing ethically sourced critical minerals outside of dominant supply chains in China and Central Asia.

What makes the Oaky Creek site so promising for high-grade antimony?

The 19.5% assay from the Oaky Creek site originates from the Baldwin Formation, a late Devonian sedimentary sequence intersected by the Namoi Fault. This major structural corridor strikes at 135° and is known to host multiple antimony-bearing vein systems. According to historical records compiled by P.W. English & Associates in 2011, the rock sample was taken from a coarse-grained stibnite occurrence—evidence of a robust hydrothermal system capable of concentrating antimony to economically significant levels.

The Oaky Creek historical workings mark one of several high-priority areas within the broader EL9732 licence. These include East Hills and Horsley, each identified through desktop analysis and geophysical interpretations. Red Mountain Mining believes that mineralisation at Armidale is of orogenic origin, paralleling the system at the Hillgrove Project, operated by Larvotto Resources, which lies to the east. Hillgrove has long served as a geological analogue for antimony-gold systems across New South Wales.

This geological interpretation is crucial, as orogenic systems typically exhibit depth continuity, meaning that mineralisation encountered at surface may extend downwards through structurally controlled pathways. The coarse nature of the stibnite, proximity to fault structures, and presence of brecciated and altered host rocks all support the company’s hypothesis that the Namoi Fault acts as the primary control for the stibnite mineralisation.

How does Armidale’s geology support future exploration?

Red Mountain’s Armidale project sits within the Southern New England Orogen, a tectonic belt rich in folded Carboniferous metasediments, ultramafic intrusions, and structural complexity. The Tamworth Belt, where the licence is located, was formed in a subduction-related forearc environment and is intersected by serpentinite mélanges from the Great Serpentinite Belt. These geological features offer ideal conditions for structurally driven hydrothermal fluid movement, which forms the basis of stibnite emplacement.

Field evidence indicates that stibnite veins occur in brecciated carbonate and altered sandstone, consistent with hydrothermal fluid flow during periods of regional compression. The combination of carbonate breccias and siliceous gangue, as seen in the high-grade sample, suggests strong mineralisation potential. Structural geologists working with Red Mountain Mining have interpreted the Namoi Fault as the dominant mineral conduit. The targeting strategy will now focus on verifying this control through ground sampling and mapping.

Why is antimony’s price rally important for Red Mountain Mining?

The market context surrounding this find is equally important. Antimony prices, now trading above US$58,000 per tonne, reflect tightening global supply and increasing demand from flame retardants, electronics, military-grade munitions, and energy storage batteries. The metal has become strategically vital, with its inclusion on critical mineral lists in Australia, the United States, and the European Union.

Global supply remains concentrated, with over 70% of the world’s antimony production sourced from China and Tajikistan. This concentration, combined with environmental restrictions and geopolitical uncertainty, is driving industrial consumers to diversify supply chains. Projects like Red Mountain’s Armidale Antimony-Gold Project are emerging as key to these efforts.

Australia’s political stability, strong ESG frameworks, and proximity to Asian markets enhance the strategic value of domestic antimony sources. If exploration at Armidale leads to a defined resource, the project could position Red Mountain Mining as a key player in allied supply strategies for critical minerals.

What does the stock market think about this announcement?

Despite the potential of this find, Red Mountain Mining’s share price has remained relatively subdued. As of April 1, 2025, the stock (ASX: RMX) was trading at A$0.0080, with a market capitalisation of approximately A$4.185 million. Over the past 52 weeks, the share price has fluctuated between a high of A$0.0160 and a low of A$0.0010, reflecting high volatility typical of early-stage explorers.

The muted price response suggests that investors may be taking a wait-and-see approach, possibly awaiting additional results from surface sampling or early drilling campaigns. However, there are signs of increasing confidence from within the company. On March 26, Managing Director Lincoln Liu increased his shareholding by 200,000 shares, taking his total to 3 million. Insider buying often serves as a bullish signal, especially when it coincides with a potentially transformational announcement.

Currently, RMX receives limited coverage from institutional analysts, and no consensus recommendations or target prices have been published. This lack of visibility may impact trading volumes, but it also means that successful early exploration results could re-rate the stock sharply if a defined resource is proven.

What’s next for Red Mountain Mining at Armidale?

Red Mountain Mining is currently in the final stages of securing land access agreements for Oaky Creek and its other high-priority zones. The company has conducted land ownership research and begun engaging directly with stakeholders to facilitate its upcoming ground campaign. The exploration plan includes mapping, surface sampling, and desktop reviews to identify mineralised trends and anomalies not captured in historic data.

The company’s strategy is to follow up on high-grade occurrences along the Namoi Fault and to fill in gaps in historical geochemical coverage. With no drilling conducted to date, the next phase of exploration will aim to define surface continuity and vector toward potential drill targets. Should the mineralisation extend laterally or vertically, shallow drilling will likely be considered to test structural persistence and grade continuity.

How does Armidale fit into Red Mountain’s critical minerals portfolio?

The Armidale project is part of Red Mountain’s broader critical minerals and gold exploration portfolio. The company is also advancing its Fry Lake Project in the Red Lake district of Ontario, the Monjebup Rare Earths Project in Western Australia, and lithium assets in Nevada. This diverse positioning allows Red Mountain to mitigate risk while participating in several high-demand commodity markets.

The confirmation of high-grade antimony at Armidale adds a valuable critical minerals component to Red Mountain’s pipeline. If exploration validates continuity and scale, the project could transition from an early-stage curiosity to a cornerstone asset, contributing to both national resource security and shareholder value.

For now, Red Mountain Mining remains a speculative but potentially undervalued stock in the ASX junior resources space. The upcoming sampling program at Armidale Antimony-Gold Project will be closely watched by investors, geologists, and strategic mineral stakeholders alike. If subsequent results reinforce the significance of the 19.5% antimony assay, this could mark the beginning of a transformative chapter for the company.