A Diamantina Laboratories petrology study has confirmed the presence of heavy rare earth minerals xenotime and florencite across the Mt Mansbridge Project in Western Australia’s East Kimberley region. 

This means Red Mountain has the opportunity to determine whether there is an economically viable concentration of rare earths in the Kimberley – an area that has long been overlooked.

With already a significant number of REE deposits located in the East Kimberley region of WA such as Browns Range, John Galt, Brockman, and Cummins Range, Red Mountain (ASX:RMX) believes Australia’s northwest is an emerging rare earths province.

The minerals were found within quartz veining and the associated wall rock alteration, where three samples were taken from the recently announced mineralised zone from drill hole MMRC002 at the Solo prospect.

These samples have now been sent for description by Roger Townend at Diamantina Laboratories and reviewed using optical and scanning electron microscope techniques.

Giant step forward in REE discovery

RMX non-executive chairman Troy Flannery said the petrological confirmation of heavy rare earth mineral xenotime is a “significant step in the exploration for heavy rare earths.”

“With a similar xenotime mineralisation to the Browns Range Project, along with its close proximity to Northern Minerals (ASX:NTU) processing facility, makes the Mt Mansbridge project highly prospective.”

Access tracks have now been established at the Mt Mansbridge project with heritage clearance achieved.

Plans are in place to resume the drill program at the end of the Kimberly wet season in early 2022.

Significance of Xenotime mineralisation

Xenotime is a REE phosphate mineral, whose major component is yttrium orthophosphate (YPO4).

The rare earths dysprosium, erbium, terbium, and ytterbium (all replacing yttrium) are the expressive secondary components of xenotime.

Xenotime’s significance is the mix of REE in the mineral where the lanthanide content runs about two-thirds yttrium and largely a source of heavy lanthanide metals (dysprosium, ytterbium, erbium, and gadolinium).

Secondly, the processing of rare earths involves the separation of each REE in sequence and can be a costly process.

As xenotime is relatively low in light REEs (lanthanum and cerium) whilst having high concentrations of valuable dysprosium and terbium, making it likely to be higher in basket price value and anticipated to be lower in processing cost per tonne of rock.




This article was developed in collaboration with Red Mountain, a Stockhead advertiser at the time of publishing.


This article does not constitute financial product advice. You should consider obtaining independent advice before making any financial decisions.