RareX Limited (ASX:REE) announced on 21 September 2026 the identification of a broad zone of anomalous copper mineralisation in drill hole KRC012 at the Niobe Prospect, part of its Khaleesi Project in Western Australia. Portable XRF readings indicate copper enrichment over about 74 metres, from 77 metres to 151 metres downhole.

The readings are preliminary field values, and certified laboratory assays are expected in four to six weeks.

About RareX

RareX Limited is a critical minerals company that specialises in rare earths, gallium, niobium and scandium in hard rock carbonatites. It is based in Subiaco, Western Australia, and James Durrant is Managing Director and CEO.

Its exploration focus is the Khaleesi Project in the East Yilgarn region, a district-scale alkaline intrusive complex with elevated gallium and niobium, and the Piper Project in the Northern Territory. Its engineering focus is the metallurgy of the Cummins Range Project, a carbonatite-hosted rare earths and phosphate project. RareX has formed a consortium with Iluka and made a proposal for the Mrima Hill rare earth project in Kenya, and holds investments in Kincora Copper, Cosmos Exploration and Canada Rare Earth Corporation. The Khaleesi Project covers about 966 square kilometres and was acquired in May 2024 following recognition of the Khaleesi Alkaline Intrusive Complex.

According to the company, the nearest deposit of significance, Mulga Rocks, is less than five kilometres from the project, the Tropicana gold deposit is about 100 kilometres to the north and the Ponton dyke rare earth occurrences are about 45 kilometres to the south.

Latest Development: Niobe Copper Intersection (21 September 2026)

Six drill holes totalling 805 metres were drilled at a coincident gravity and magnetic anomaly at Niobe, on two drill lines 400 metres apart. All holes except KRC009 intersected hydrothermally altered pyroxenite beneath a roof pendant of syenite, cut by porphyry fingers from under one metre to four metres wide. Sulphides in the pyroxenite are mostly less than 0.5% to 1% fine disseminated pyrite with trace chalcopyrite, locally becoming semi-massive with up to 20% pyrite.

KRC012, the final hole on the southern line, returned portable XRF readings averaging 940 parts per million copper over 74 metres from 77 metres, with multiple readings above 1,500 parts per million and a peak of 5,724 parts per million, or 0.57%. Hole KRC007, 900 metres to the north-east, also showed elevated copper, with 8 metres at 960 parts per million. The company stated that the style of mineralisation has not been determined and that the alteration and sulphide textures are typical of propylitic alteration, suggesting the drilling is in an outer halo of the system. Future exploration will focus on vectoring toward the source of fluids, where copper grades may increase.

A core photograph in the release shows drill metres 125 to 130 in KRC012 with pyroxenite and sulphide alteration, annotated with sulphide estimates and portable XRF copper readings. The company notes that visual estimates of mineral abundance should not be treated as a substitute for laboratory analysis where grade is the Factor of principal economic interest.

The company cautioned that the XRF results are preliminary field values, not equivalent to certified laboratory assays and not a proxy for quantitative analysis. Samples from the KRC012 interval will be submitted for independent laboratory analysis with a full suite including gold, to help fingerprint the style of mineralisation.

Managing Director James Durrant said the scale and consistency of copper anomalism in KRC012 warrants follow-up, and that alteration vectors suggest the hotter part of the system is yet to be found. Copper now sits alongside the gallium, niobium and rare earth potential already being evaluated at Niobe. RareX is interpreting the full Niobe drilling program and planning the next phase of work.

Niobe is one of five priority targets within the Khaleesi Alkaline Intrusive Complex tested by the company's maiden Reverse Circulation Drilling program. The complex has also seen tens of thousands of metres of historical aircore drilling by companies including AngloGold Ashanti, IGO and Fortescue, which the company says mostly stopped on reaching basement and left the basement intrusive complex largely untested.

Risks and Uncertainties

The copper results are portable XRF readings on drill spoil, which the company describes as preliminary field values. They are not laboratory assays, and actual grades and widths of any mineralisation remain to be determined.

The company states that the style of mineralisation is not yet determined and that the alteration suggests an outer halo of the system. Higher copper grades have not been demonstrated.

The announcement does not report a Mineral Resource for the Khaleesi Project. The Niobe copper intersection comes from one of six holes in a maiden program, and KRC009 did not intersect the altered pyroxenite.

Timing of laboratory assays and of the next drilling phase is not fixed, and the company's wider rare earths and gallium work, including Cummins Range, depends on metallurgy, approvals and funding.

Milestones to Watch

  • Laboratory assay results for the KRC012 mineralised interval, expected in four to six weeks, including gold.
  • Interpretation of the full Niobe drilling program and thin section work to determine the style of mineralisation.
  • Planning and timing of the next phase of work, including assessment of the extent of the copper mineralisation.
  • Results from the other priority targets in the Khaleesi Alkaline Intrusive Complex.