Gold Mountain has reported four rock-chip samples above the laboratory’s 10,000 ppm tungsten limit at the historical Malhada do Angico mine in Brazil. The results expand the company’s exploration case, but the samples are non-representative and drilling has yet to begin.
- Four of 10 rock-chip samples exceeded 10,000 ppm tungsten
- Minimum average grade of approximately 0.82% WO₃
- Around 4 kilometres of mapped skarn strike across GMN and EMPG tenements
- Magnetic and LiDAR surveys scheduled for November 2026
- Diamond drilling remains subject to permits and acquisition due diligence
Four Samples Exceed Tungsten Assay Limit
Gold Mountain Limited (ASX:GMN) has found four rock-chip samples above the laboratory’s 10,000 parts per million tungsten limit at the historical Malhada do Angico mine in northeastern Brazil. The assays equate to more than approximately 1.261% tungsten trioxide (WO₃), with the actual grades still to be established through over-limit analysis.
The ten samples returned results ranging from 0.12% to above 1.261% WO₃ and produced a calculated average of about 0.82% WO₃. That figure is explicitly a minimum, because the four over-limit results were capped at the laboratory’s upper detection threshold. Two of the over-limit samples came from historical mine waste rather than intact outcrop, a distinction that matters when considering what the results say about in-situ mineralisation.
Skarn Strike Extends Beyond Historical Workings
Gold Mountain’s most notable in-situ-style result came from sample MARK0001, which returned 1.07% WO₃ in the southeastern part of the EMPG mining application. The company said the result supports further investigation of an eastern skarn belt outside the principal historical mine workings.
Geological mapping has identified roughly 2,000 metres of skarn strike around the main historical workings across Gold Mountain’s existing Logradouro tenements and the adjacent EMPG ground. A further approximately 2,000 metres of skarn, along with minor historical workings, has been mapped in the eastern section of the EMPG application. The project is covered by the October tungsten acquisition right, under which Gold Mountain holds an exclusive 12-month right to acquire the 857.53-hectare mining application while it completes due diligence.
Stream-sediment results provide another layer of targeting information, with tungsten and bismuth anomalies occurring together in parts of the tenement and molybdenum anomalism spread more widely. Gold Mountain cautioned that the strongest stream-sediment values may be partly influenced by contamination from historical mining, although other strong anomalies occur away from known workings. The company has also identified a potentially mineralised area in the central part of the application beyond the mapped skarn zones.
Surveys and Tailings Tests Set Up the Next Phase
High-resolution magnetic and LiDAR surveys are scheduled for November, with the contractor mobilising after the work was approved. Magnetic data is intended to sharpen the interpretation of structures controlling tungsten mineralisation, while LiDAR should help locate old workings, improve geological mapping and support drill planning.
Auger drilling of historical tailings is partly complete, and samples are being assembled for metallurgical testing. The planned work will assess tungsten grades, penalty elements and whether the tailings could produce a saleable WO₃ concentrate. Detailed mapping and possible soil-sampling grids are also planned across the eastern skarn belt and central anomalous areas.
Drilling Still Depends on Permits and Due Diligence
Diamond drilling permits are being progressed, with drilling intended to test the historical workings, mapped skarn occurrences and priority targets generated by the geophysical and geochemical work. No drilling, mineral resource estimate or representative bulk-grade assessment has been reported in this release.
That leaves the announcement as an encouraging exploration signal rather than evidence of a defined deposit. Grab samples are selective by nature and the company states they are not representative of mineralisation; stream-sediment anomalies can also reflect transported material or old mining disturbance. The next meaningful tests will be the over-limit assays, metallurgical results and, if approvals arrive, drill intersections that can establish continuity and scale.
Bottom Line?
The headline grades are promising, but the investment case now depends on whether selective surface results survive over-limit assays, metallurgy and eventually representative drilling.
Questions in the middle?
- What grades will the four over-limit samples return once their actual tungsten concentrations are measured?
- Can tailings testing demonstrate recoverable WO₃ concentrate while keeping penalty elements within acceptable levels?
- Will permits and due diligence allow drilling and the potential acquisition to proceed on the planned timetable?