St George Mining Ltd (ASX:SGQ) has confirmed a major new discovery of high-grade rare earths and niobium at its 100%-owned Araxá Project in Minas Gerais, Brazil, with assays from the first batch of reverse circulation (RC) drilling at the previously unexplored East Araxá location returning standout results.
The discovery sits about 1 kilometre east of Araxá’s existing mineral resource estimate (MRE) and highlights the potential to substantially expand what is already regarded as the highest-grade undeveloped JORC-compliant rare earths resource globally.
Plan view map of the Project area showing the location of the RC drilling at East Araxá relative to the MRE.
Major intercepts and high-value rare earths
Assays from the first three RC drill holes at East Araxá returned thick, near-surface intercepts, including:
- 48 metres at 5.71% total rare earth oxides (TREO) from 2 metres, including 15 metres at 12.61% TREO from 4 metres.
- 32 metres at 1.04% niobium pentoxide (Nb₂O₅) from 11 metres, including 6 metres at 2.41% TREO from 11 metres.
- 40 metres at 2.62% TREO and 1.05% Nb₂O₅ from surface, including 8 metres at 4.38% TREO from 35 metres.
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Section showing high-grade TREO intercepts (cut-off 1% TREO) and high-grade intercepts Nb2O5% (cut-off 0.2% Nb2O5). Note that drill hole AXRC009 is projected from adjacent cross section.
Grades reached up to 16.87% TREO and 4.06% Nb₂O₅, with high proportions of magnet and heavy rare earths. Notably, neodymium-praseodymium (NdPr) values were up to 3.96% (39,600 ppm), while elevated levels of dysprosium, terbium, lutetium and gadolinium contributed to a strong heavy rare earth component.
The assays also revealed unusually high samarium grades — up to 2,600 ppm — a key element used in samarium-cobalt magnets, which are critical in advanced military applications such as F-35 fighter jets.
‘Compelling development opportunity’
St George executive chairman John Prineas said the East Araxá drilling underscored the scale and importance of the new find.
“We are delighted with the results from the follow-up deeper drilling at East Araxá, which has confirmed the continuity and depth extent of this near-surface, high-grade rare earths and niobium discovery,” Prineas said.
“The volume of mineralisation being defined by the RC drilling… points to the potential for a significant addition to the Araxá MRE, already the highest-grade undeveloped JORC-compliant rare earths resource globally,” he added.
“With governments and private enterprise globally looking for secure and reliable new supplies of rare earths and niobium, our Araxá Project — a carbonatite-hosted deposit in the same style as the two major producing rare earths mines outside of China, Mountain Pass in California and Mt Weld in Western Australia — is gaining recognition as a compelling development opportunity.”
Read more: St George Mining confirms high-grade rare earths and niobium at Araxá Project
Resource growth and strategy
St George is advancing RC drilling at East Araxá with an inferred resource targeted for the December quarter. Three diamond rigs are also operating around the clock on expansion drilling along strike of the current MRE, with first assays expected in coming weeks.
The Araxá Project already boasts a JORC resource of 40.6 million tonnes at 4.13% TREO and 41.2 million tonnes at 0.68% Nb₂O₅. The mineralisation starts from surface, is free-digging, and sits in a well-established mining region with strong infrastructure and government support.
St George has also entered a strategic alliance with US-based REAlloys Inc, which holds defence supply contracts, to advance testwork and potential offtake for Araxá-sourced rare earth products.
Read more: St George Mining forges US downstream alliance to commercialise Araxá rare earths
Next steps
With more than 8,000 metres of drilling still to be completed and an updated resource estimate in sight, St George says it expects “strong newsflow” through the rest of 2025.
“The high proportion of magnet rare earths — both light and heavy — at East Araxá is very impressive,” Prineas said. “St George, through its downstream strategic alliance in the US, is perfectly positioned to contribute to establishing a US domestic supply chain for these important magnets.”