Highlights

• Maiden basement drilling at Khaleesi comprised 22 RC holes for 1,953 metres across five prospects, representing RareX's first systematic investigation of the basement geology of the Khaleesi Alkaline Intrusive Complex.

• Laboratory assays confirm a copper-nickel sulphide system hosted within a layered mafic intrusion at the Niobe Copper prospect, with a best intersection of 40 metres at 0.13% copper and 374 ppm nickel, including 24 metres at 0.16% copper and 543 ppm nickel.

• Gallium-rich regolith has been confirmed overlying the Niobe granite, with notable intersections including 20 metres at 73 grams per tonne Ga2O3 and 16 metres at 75 grams per tonne Ga2O3, alongside broad granite-hosted gallium zones at the Nb prospect.

• An IP geophysical survey is planned to commence at Niobe in November 2026 to vector toward higher concentrations of copper sulphides, and initial gallium metallurgical test work will also commence.

RareX Limited (ASX:REE), an ASX-listed critical minerals company specialising in rare earths, gallium, niobium, and scandium, has released laboratory assay results from its maiden Reverse Circulation Drilling programme at the Khaleesi Project in the East Yilgarn region of Western Australia. The programme, comprising 22 holes for 1,953 metres across five prospects, represents the company's first drilling into the basement rocks of the Khaleesi Alkaline Intrusive Complex and has delivered a range of outcomes spanning copper-nickel sulphide mineralisation, gallium-rich regolith, and rare earth element occurrences.

Copper-Nickel Sulphide System at Niobe Copper

Six holes for 805 metres were drilled at the Niobe Copper prospect on two east-west lines 400 metres apart, testing a coincident gravity and magnetic anomaly. Five of the six holes intersected a layered mafic intrusion beneath a roof of felsic intrusive rocks. Multi-element geochemistry confirms the intrusion is an iron-titanium-rich gabbro, with its upper portion plagioclase-rich and a more magnesium-rich phase occurring at its base. The best hole, KRC012, returned a 40-metre intersection at 0.13% copper and 374 parts per million nickel from 110 metres, including 24 metres at 0.16% copper and 543 parts per million nickel from 126 metres.

The association of copper with nickel and cobalt within a mafic intrusion is characteristic of a magmatic sulphide system, with the disseminated to locally semi-massive pyrite and chalcopyrite mineralisation consistent with this interpretation. An important additional observation is the depletion of magnetite within the best copper zone in KRC012, together with propylitic alteration, which indicates a hydrothermal overprint. This is geologically significant because hydrothermal fluids have the potential to concentrate copper into structurally or chemically favourable sites at higher grades than the disseminated magmatic sulphides intersected to date. The Niobe intrusion remains largely untested — two holes finished within 2-6 metres of entering the gabbro and have not tested the mineralised position intersected in KRC012 elsewhere along the 400-metre separation between drill lines.

Gallium-Rich Regolith Across Multiple Prospects

Ten shallow holes at Niobe Gallium confirmed gallium enrichment in clay-rich saprolite overlying granite. Gallium is absent in the upper 8-12 metres of alluvial sand but is enriched in the underlying saprolite, with grades reaching 60-75 grams per tonne Ga2O3. The fresh granite beneath the saprolite itself carries approximately 50 grams per tonne Ga2O3, confirming the granite as the source of the gallium and suggesting that the saprolite enrichment reflects weathering and concentration processes. Best intersections included 38 metres at 62 grams per tonne from 4 metres (including 20 metres at 73 grams per tonne) and 86 metres at 53 grams per tonne from 4 metres (including 16 metres at 75 grams per tonne).

Gallium enrichment was also observed at the Nb prospect, where two holes intersected an alkaline A-type granite with broad gallium zones including 91 metres at 59 grams per tonne Ga2O3 from 24 metres. At the Rim prospect, in addition to a near-surface tungsten intersection of 8 metres at 0.09% WO3 from 20 metres, the underlying granite returned 68 metres at 51 grams per tonne Ga2O3 from 28 metres along with elevated rare earth element content. Gallium is increasingly relevant as a critical mineral due to its use in semiconductors and solar panels, with Supply concentrated in a small number of jurisdictions globally.

Next Steps: IP Survey, Metallurgical Work, and Further Drilling

An induced polarisation geophysical survey is planned to commence at Niobe in November 2026. IP surveys measure the chargeability of subsurface material, providing a geophysical vector toward zones of higher sulphide development that may host stronger copper-nickel mineralisation than the disseminated sulphides intersected to date. The depletion of magnetite within the best copper zone in KRC012 is also a geophysical vector — the untested non-magnetic portions of the Niobe gravity anomaly, which the current programme did not drill, will be assessed alongside chargeability anomalies from the planned IP survey.

Concurrent with the geophysical work, initial metallurgical test work will commence on composite samples of gallium-enriched saprolite from the Niobe Gallium prospect. This test work will characterise how gallium is hosted within the clay-rich saprolite and assess its potential recoverability, to guide the next phase of evaluation. Thin section petrography will also be undertaken to confirm the style of the copper-nickel mineralisation. The planned deepening of holes that finished at the top of the intrusion at KRC010 and KRC011 is among the follow-up drilling Options under consideration.

Key Insights

The maiden Khaleesi basement drilling programme has delivered a diverse range of outcomes across five prospects in a single campaign, including a confirmed copper-nickel sulphide system, gallium-rich regolith across three prospects, rare earth element occurrences, and a near-surface tungsten result. This breadth of findings across a single alkaline intrusive complex reflects the geological diversity of these types of geological environments.

The most significant near-term focus will be the results of the IP survey at Niobe, which will determine whether stronger chargeability anomalies — indicative of more concentrated sulphide mineralisation — are present beyond the magnetic zones already tested. If the IP survey identifies compelling targets in the non-magnetic portions of the gravity anomaly, this could provide a clear vector for follow-up drilling aimed at finding higher-grade concentrations of copper-nickel sulphides.