Red Mountain Drills 3km Antimony System in Australia’s Premier Sb Province

Red Mountain Mining has kicked off maiden RC drilling at its Oaky Creek prospect within the Armidale Antimony-Gold Project — 17 holes testing a 3km system backed by 39.3% Sb rock chips, a DDIP anomaly modelled to 200m depth, and a geological analogue to Larvotto's AU$660 million Hillgrove deposit.
By William Hadrian -
  • Red Mountain Mining has commenced a 17-hole maiden RC drilling program at Oaky Creek within the 391 km² Armidale Antimony-Gold Project, with assays expected in Q2 FY27 (October–December 2026).
  • Surface rock chips have returned up to 39.3% antimony and 1.09ppm gold, while a July 2026 DDIP survey modelled a coherent chargeability anomaly extending to at least 200m depth and 400m strike.
  • May 2026 metallurgical test work confirmed 85% antimony recovery at 51.8% concentrate grade, resolving processing risk before the first drill assay is returned.
  • Oaky Creek is described as geologically analogous to Larvotto Resources' Hillgrove Project — Australia's largest known antimony resource — which carries a market capitalisation of approximately AU$660 million.
  • Three near-term catalysts are scheduled: Pioneer Tungsten assays (Montana, early September 2026), Armidale RC drilling completion (~3 weeks), and Oaky Creek assay results (Q2 FY27).
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Drilling begins at Red Mountain’s Armidale Antimony-Gold Project

Red Mountain Mining has commenced its maiden RC drilling program at the Oaky Creek prospect within the 391 km² Armidale Antimony-Gold Project in New South Wales. 17 holes are planned over approximately 3 weeks, testing priority targets defined by 12 months of surface geochemical work. Assays are expected next quarter (Q2 FY27, October-December 2026). What makes this the drill-bit moment investors have been waiting for: the program tests a system RMX believes is analogous to Larvotto’s Hillgrove — a comparison that carries significant discovery leverage in Australia’s premier antimony province.

What the maiden program is testing

The RC program will drill test three specific targets backed by rock chip, conventional soil and auger soil data completed over the past 12 months:

  • The coherent 300m x 30m Oaky Creek South Main Grid antimony-arsenic auger soil anomaly, which has returned rock chip results of up to 39.3% Sb and 1.09ppm Au
  • Historical workings and outcropping quartz-carbonate-stibnite veins at Oaky Creek North
  • The Sb-bearing creek exposure to the north

These are drill-ready, data-supported targets — not speculative wildcatting. Drilling started later than the contractor initially indicated due to rig availability influenced by prior wet weather and other unforeseen circumstances, but the program is now underway.

The Oaky Creek story — a 3km orogenic antimony system

Oaky Creek is RMX’s most advanced target: a ~3km-long orogenic antimony system with multiple drill-ready targets. The exploration build-up began with an initial 50m x 100m soil grid, followed by a ~1,300-sample infill hand auger campaign completed across late 2025 and early 2026. That work tightened the grid to define five high-priority targets for drill testing.

The July 2026 DDIP survey result materially expands the target. Modelling revealed a coherent NNE-SSW-striking, steeply SE-dipping chargeability anomaly beneath and at least 300m southwest from outcropping quartz-carbonate-stibnite veins at the Oaky Creek South Workings. The anomaly shows a peak observed chargeability of over 7.2 mV/V, compared to background values that typically range from 2 to 3 mV/V. It is modelled to extend from surface to a depth of at least 200m, and over a strike extent of at least 400m — compared to the ~120m strike of surface vein mineralisation. It strengthens to the SSW and remains open in that direction.

Oaky Creek Target Data Dashboard

Evidence Type Key Result Target Significance
Rock chip sampling Up to 39.3% Sb, 1.09ppm Au High-grade surface mineralisation
Soil anomaly ~1.5km >2ppm Sb (north) + ~1km (south) Defines strike continuity
Auger infill (~1,300 samples) Defined 5 priority targets Drill-ready definition
DDIP survey (Jul 2026) Peak 7.2 mV/V vs 2–3 mV/V background; modelled to ≥200m depth, ≥400m strike Expands Oaky Creek South target at depth
Metallurgy (May 2026) 51.8% concentrate grade, 85% Sb recovery Confirms processing potential

The ~3km system is described as analogous to Larvotto Resources’ (ASX: LRV; Market Cap. ~AU$660 million) Hillgrove Project. This is a geological analogue comparison based on system scale and style of mineralisation — RMX has not stated it holds an equivalent resource or valuation. What the comparison tells you: if Oaky Creek delivers a similar strike extent and grade profile to Hillgrove, the discovery leverage is substantial.

Antimony explained — why this critical mineral matters to investors

Antimony is a metalloid element classed as a critical mineral due to its strategic importance in defence, batteries, flame retardants, and other high-tech applications. Western supply-chain concerns have intensified as China controls roughly 80% of global antimony production, making domestic sources a priority for governments and industry.

An “orogenic antimony-gold vein system” refers to mineralisation formed during mountain-building events (orogeny). Tectonic compression generates faults and fractures, creating pathways for hot, metal-rich fluids from deep within the Earth’s crust. These fluids deposit antimony and gold as they cool, forming quartz-carbonate-stibnite veins and breccias. The system at Oaky Creek exhibits these classic characteristics — outcropping veins, historical workings, and a coherent geochemical footprint extending ~3km along strike.

The Southern New England Orogen (SNEO) is recognised as Australia’s premier antimony province. It hosts Larvotto’s Hillgrove deposit, Australia’s largest known antimony resource and the 8th largest globally. The Peel Fault, which runs through RMX’s tenement, hosts over 400 known orogenic gold and base metal occurrences over a strike extent exceeding 400km. Despite this world-class potential, the system remains underexplored, with less than 200 mostly shallow drillholes over its length, the majority focused on discrete prospects.

Southern New England Orogen Context

The SNEO is recognised as Australia’s premier antimony province. The Peel Fault System has recognised world-class mineral potential, with over 400 known orogenic gold and base metal mineral occurrences along its over 400km strike extent, but is underexplored, with less than 200 mostly shallow drillholes over its length.

What this tells you as an investor: high-grade antimony surface results in an underexplored, premier province create discovery leverage. The geological setting is proven, the system scale is material, and the drill-bit moment is now.

Beyond Armidale — the broader critical minerals portfolio

Red Mountain positions itself as a US + Australia critical minerals explorer in Tier-1 districts. The near-term US catalyst is assay results from the Pioneer Tungsten Project in Montana, expected early September 2026. The project encompasses the same geology and exhibits the same skarn-style mineralisation as the 6.8Mt Gentung tungsten resource (owned by NASDAQ: ALM).

RMX’s broader critical minerals portfolio:

  • Pioneer Tungsten Project, Montana — same geology/skarn-style mineralisation as the 6.8Mt Gentung resource (NASDAQ: ALM)
  • Utah Antimony Project — adjacent to Antimony Canyon (ASX: AT4)
  • Thompson Falls Antimony Project — up to 36.5% Sb at historical mines, near the NYSE: UAMY smelter
  • Idaho Antimony Project

What this portfolio structure tells you: multiple near-term news catalysts across two jurisdictions. If Armidale delivers, RMX has optionality to scale discovery across multiple critical mineral systems.

What’s next for Red Mountain investors

The near-term catalyst calendar includes three expected events:

  1. Pioneer Tungsten (Montana) assay results — early September 2026
  2. Armidale RC drilling completion — ~3 weeks from commencement
  3. Oaky Creek assay results — expected next quarter (Q2 FY27, October-December 2026)

Further exploration at Oaky Creek is dependent on drilling outcomes. If the maiden program confirms continuity and grade at depth, the five high-priority targets defined by the auger campaign become a multi-phase drilling pipeline. If it doesn’t, the exploration thesis resets, and capital reallocates to other portfolio assets.

What you are looking at: maiden drilling into a data-backed 3km system in Australia’s premier antimony province. The DDIP survey extended the target to ≥200m depth and ≥400m strike. The metallurgical test delivered 51.8% concentrate grade at 85% Sb recovery. The analogue is Larvotto’s Hillgrove, which carries a market capitalisation of ~AU$660 million. Assays are the key upcoming catalyst, expected next quarter. If the drill confirms what the surface work suggests, the discovery leverage is material.

Ready to Explore Red Mountain’s Full Critical Minerals Strategy?

RMX has commenced its maiden drilling program at Oaky Creek, testing a 3km antimony-gold system in Australia’s premier antimony province. The company is backed by systematic surface work, geophysics modelling a coherent chargeability anomaly to ≥200m depth, and metallurgy confirming 85% antimony recovery at 51.8% concentrate grade.

Drilling at Armidale is just one catalyst in a broader portfolio that includes tungsten and antimony projects across Montana, Utah, and Idaho. For a complete view of RMX’s critical minerals pipeline, current project timelines, and upcoming assay catalysts, visit the Red Mountain Mining investor centre.


Frequently Asked Questions

What is Red Mountain Mining's Armidale Antimony-Gold Project?

The Armidale Antimony-Gold Project is a 391 km² exploration tenement in New South Wales held by Red Mountain Mining (ASX: RMX), located within the Southern New England Orogen — Australia's premier antimony province. The project's most advanced target, Oaky Creek, hosts a ~3km orogenic antimony-gold system with high-grade surface results and drill-ready geophysical targets.

What are the results of Red Mountain's Oaky Creek surface sampling?

Rock chip sampling at Oaky Creek has returned grades of up to 39.3% antimony and 1.09ppm gold, while a July 2026 DDIP geophysical survey modelled a coherent chargeability anomaly extending to at least 200m depth and 400m strike — more than three times the ~120m strike of surface vein mineralisation.

When will Red Mountain Mining's Armidale drilling assay results be released?

Assay results from the maiden 17-hole RC drilling program at Oaky Creek are expected in Q2 FY27, covering October to December 2026. A separate near-term catalyst — assay results from the Pioneer Tungsten Project in Montana — is expected in early September 2026.

Why is antimony considered a critical mineral for investors?

Antimony is classified as a critical mineral due to its strategic role in defence applications, batteries, and flame retardants, combined with severe supply concentration — China controls roughly 80% of global production. This makes domestic antimony discoveries in Western jurisdictions a priority for governments and industry, adding a structural demand driver beyond commodity price cycles.

How does Red Mountain's Oaky Creek compare to Larvotto's Hillgrove project?

RMX describes Oaky Creek as geologically analogous to Larvotto Resources' Hillgrove Project — Australia's largest known antimony resource and the 8th largest globally — based on system scale and style of mineralisation within the same Southern New England Orogen. RMX has explicitly stated this is a geological comparison only and does not imply an equivalent resource size or valuation to Larvotto's ~AU$660 million market cap.

William Hadrian
By William Hadrian
Partnerships Director
William supports Discovery Alert subscribers across Australia and overseas, helping them tailor alerts, troubleshoot technical issues, and optimise platform settings to suit their workflow.
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