Altona Rare Earths, the London-listed critical materials explorer, saw its shares rise 11% to 3.11 pence on Tuesday after reporting that gallium mineralisation at its Monte Muambe project in Mozambique had exceeded pre-drilling expectations, alongside strong fluorspar results in line with commercial mining grades.
The company said final assay results from its 2025 drilling campaign were now in hand, clearing the way for the preparation of a mineral resource estimate (MRE), which it described as the next major milestone for the project.
Gallium, a critical metal used in semiconductors and defence electronics, was encountered across wide, consistent intercepts averaging 18 metres, with a weighted average grade of 63 grams per tonne of gallium oxide and individual samples reaching as high as 149 grams per tonne.
Chief executive Cedric Simonet said the gallium results showed exceptional consistency and had surpassed internal expectations, adding that while the deposit type was novel and much work remained to establish commercial viability, the results strengthened the case for further investment in gallium studies.
A metallurgical testing programme, initiated last week, will assess how much gallium can be recovered from fluorspar tailings, the waste material left over from processing the project's primary mineral.
Fluorspar, a mineral used in steel production, chemicals and aluminium smelting, returned a weighted average grade of 30% calcium fluoride across significant intercepts, within the 20% to 40% range typically considered viable for open-pit mining operations.
The standout fluorspar result came from hole MM156, which returned 30 metres at 42.5% calcium fluoride from surface, the highest grade-times-length intercept recorded at the project to date.
Altona noted that its 2025 drilling covered only around 40% of the surface area showing soil anomalies for both minerals, leaving the remaining 60% undrilled and offering scope for further mineralisation to be identified.