Red Mountain Drills First Holes at 3km Antimony Anomaly in Australia’s Top Sb Belt
Key Takeaways
- Red Mountain Mining has commenced a maiden 17-hole RC drilling program at the Oaky Creek prospect within its 391 km² Armidale Antimony-Gold Project in NSW, with assays expected early next quarter.
- Surface rock chips at Oaky Creek South have returned up to 39.3% Sb and 1.09ppm Au across a coherent 300m x 30m soil anomaly, with the broader geochemical signature extending ~3km along strike.
- A dipole-dipole IP survey returned a peak chargeability of >7.2 mV/V — more than double background — modelled from surface to at least 200m depth over at least 400m of strike, confirming the system has depth potential.
- Metallurgical testwork has already demonstrated 85% antimony recovery and a 51.8% Sb concentrate grade from a bulk sample, removing a key technical risk before the first drill hole is completed.
- The project is geologically analogous to Larvotto Resources' Hillgrove Project — the 8th largest antimony deposit globally, carrying an AU$660 million market cap — in the same Southern New England Orogen orogenic belt.
Drilling gets underway at Red Mountain’s Armidale antimony-gold project
Red Mountain Mining has commenced its maiden RC drilling program at the Armidale Antimony-Gold Project in New South Wales. 17 holes are planned to test targets defined by 12 months of surface geochemistry at the Oaky Creek prospect. The program is expected to run for approximately three weeks, with assays anticipated early next quarter. Oaky Creek is interpreted as a ~3km-long orogenic antimony system, analogous to Larvotto Resources’ (ASX: LRV) Hillgrove Project. The 391 km² project sits in Australia’s premier antimony province, and this drilling marks the first hard test of what could be a large-scale discovery.
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Inside the maiden Oaky Creek drill program
The 17 holes will test three distinct target zones at Oaky Creek, each defined by systematic surface work that has progressively tightened drill targets over the past year.
The targets being drilled are:
- The coherent 300m x 30m Oaky Creek South Main Grid antimony-arsenic auger soil anomaly, where rock chips have returned up to 39.3% Sb and 1.09ppm Au
- Historical workings and outcropping quartz-carbonate-stibnite veins at Oaky Creek North Workings
- The antimony-bearing creek exposure north of Oaky Creek North
Why the targets are drill-ready
Red Mountain completed a ~1,300-sample infill hand auger campaign across late 2025 and early 2026, tightening the existing grid to define five high-priority targets. The work didn’t stop at soil sampling. In July 2026, a trial dipole-dipole induced polarisation (DDIP) survey returned a peak chargeability reading of >7.2 mV/V, compared to background values of 2–3 mV/V. The anomaly is modelled from surface to a depth of at least 200m over a strike of at least 400m, and remains open to the SSW. That tells you the surface geochemical signature extends at depth — precisely what you want to see before drilling.
| Data Point | Result | What It Signals |
|---|---|---|
| Auger/soil anomaly strike | ~3km | Large-scale system with potential for multiple mineralised zones |
| Peak rock chip | 39.3% Sb, 1.09ppm Au | High-grade surface expression confirms ore-grade potential |
| DDIP chargeability | >7.2 mV/V, to 200m depth | Geophysical signature extends at depth — not just surface enrichment |
| Priority targets defined | 5 | Systematic work has generated multiple drill-ready opportunities |
| Holes planned | 17 | Sufficient coverage to test strike extent and depth continuity |
Multiple independent datasets — soil geochemistry, rock chips, and geophysics — are converging on the same zones. That is what higher-confidence drill targets look like.
Understanding orogenic antimony systems
Antimony is a critical mineral for Western supply chains, particularly in flame retardants, batteries, and defence applications. Red Mountain has framed the Armidale project as a potential source of “reliable, high-quality commodity supply” to the US and Western countries — a strategic positioning that matters when government procurement is actively seeking non-Chinese antimony sources.
An “orogenic antimony-gold vein system” refers to mineralisation formed by hydrothermal fluids moving along fault structures during regional compression. The fluids deposit antimony (often as stibnite) and gold in quartz-carbonate veins. The Southern New England Orogen, where Armidale sits, is described as Australia’s premier antimony province. That geological address matters because it tells you the broader tectonic setting is favourable for large deposits.
The Hillgrove analogy is the key reference point here. Larvotto’s Hillgrove Project is the 8th largest antimony deposit globally. It lies east of Red Mountain’s ground, in the same orogenic belt. The question this drilling program will start to answer is whether Oaky Creek is the same style and scale of system.
Why Oaky Creek matters in Australia’s premier antimony province
Larvotto Resources (ASX: LRV) currently carries a market capitalisation of approximately AU$660 million, driven by its ownership of Hillgrove. That figure is a scale reference, not a valuation claim for Red Mountain. What it tells you is how the market values a large, high-grade antimony system in this jurisdiction when de-risked.
Red Mountain’s Armidale project spans 85km along the western side of the Peel Fault. The Peel Fault System hosts 400+ known orogenic gold and base metal occurrences over a strike extent of 400km+, yet it is underexplored — fewer than 200 mostly shallow drillholes have been completed across the entire system. That is the opportunity: a world-class structural corridor with minimal modern systematic exploration.
Metallurgy already de-risked
Red Mountain previously reported metallurgical testwork results on 25 May 2026. A 20kg bulk stibnite sample from Oaky Creek produced a high-quality concentrate at 51.8% Sb with 85% antimony recovery. That tells you the material is amenable to conventional flotation processing. The metallurgical hurdle, often a material risk in antimony projects, has already been cleared at pilot scale.
High-Grade Surface Expression
Rock chip samples at Oaky Creek South have returned up to 39.3% Sb and 1.09ppm Au, with the ~3km surface geochemical anomaly indicating potential for a large-scale orogenic antimony-gold vein system analogous to Larvotto’s Hillgrove Project.
What this tells you is that the geological risk is now concentrated in two areas: strike continuity and depth continuity. The drilling program is designed to test both.
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What’s next: assays and the US tungsten catalyst
The near-term newsflow calendar is straightforward. Drilling is underway now and is expected to run for approximately three weeks. Assays from the Armidale program are expected early next quarter. That gives you a clear timeline for the first hard data point.
Further exploration activity will be dependent on drill outcomes. If the results confirm the scale and grade suggested by surface work, the next phase would likely involve step-out drilling to test strike extensions and deeper mineralisation.
Red Mountain also has multiple assay catalysts across its US critical minerals portfolio:
- Pioneer Tungsten Project (Montana, USA): Assay results expected early September 2026 from the comprehensive sampling program
- Broader US portfolio: Utah Antimony, Thompson Falls, and Idaho Antimony projects provide pipeline depth across multiple jurisdictions
The drilling delay — attributed to rig availability and prior wet weather — pushed the program back from its initially indicated timeline. That is disclosed transparently in the source announcement and is a function of contractor logistics, not project fundamentals.
What you are watching for now is whether the first batch of assays from Oaky Creek confirms the surface grades at depth and along strike. If they do, the Hillgrove analogy shifts from geological observation to investment thesis.
Ready to Learn More About Red Mountain’s Antimony-Gold Discovery Potential?
Oaky Creek represents a rare chance to gain exposure to Australia’s premier antimony province at the drill-bit stage, with surface geochemistry and geophysics converging on a potential large-scale orogenic system. Assays are due early next quarter — the first hard test of whether this project mirrors Larvotto’s world-class Hillgrove deposit.
Visit the Red Mountain investor centre to track drill progress, review the company’s metallurgical testwork, and explore the full scope of its critical minerals portfolio across Australia and the United States.