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Highlight

  • Red Mountain Mining identifies stibnite, the main ore of antimony, at both Oaky Creek North and South in NSW.

  • Discovery could confirm over 1km of mineralised strike length, with further assays pending.

  • Global antimony prices surge past $60,000/tonne amid Chinese export ban and tightening supply.

Red Mountain Mining (ASX:RMX) has made a significant breakthrough in its New South Wales exploration campaign, reporting the discovery of stibnite — the primary ore of antimony — at both its Oaky Creek North and South prospects near Armidale. The development signals the potential presence of a major antimony-gold system and comes amid soaring global antimony prices and tightening supply chains.

The coarse-grained stibnite mineralisation was identified in quartz vein-hosted structures, with multiple parallel veins interpreted across the project area. According to Red Mountain’s update to the ASX on Monday, the company believes it has uncovered an inferred mineralised system spanning over one kilometre in strike length at the Oaky Creek North site alone. 

Notably, the company observed a distinct geological orientation between the two prospects. While the mineralised trend at Oaky Creek North runs northwest, the Oaky Creek South trend extends northeast. Red Mountain attributes this directional change to movement along the Namoi Fault, a significant geological feature that intersects the project area.

Red Mountain is positioning the discovery as a win not only for its own exploration ambitions but also within the context of strategic resource security.

“Antimony is strategically important in sectors where thermal stability and performance under stress are considered critical,” the company stated, highlighting its use in defence systems, semiconductors, and household electronics.

The timing of the discovery aligns with a sharp rise in global antimony prices, which have surged to over $60,000 USD per tonne, driven by China’s recent export ban and overall tightening supply of the metal. 

Over 1,000 soil and rock chip samples have already been collected across the Oaky Creek area following the initial discovery. These samples are now undergoing assay analysis at Intertek laboratories, with results expected to inform the next stage of exploration planning.

Beyond New South Wales, Red Mountain is also ramping up exploration at its Kiabye gold project in Western Australia, where early work in May focused on identifying geochemical anomalies. Initial results from that program are still pending.

The market reacted swiftly to the Oaky Creek news, with RMX shares rising over 28% in Monday trade to 0.9 cents.