Mount Ridley Mines Ltd (ASX:MRD) has unveiled a substantial heavy rare earth resource at its Mount Ridley Project in Western Australia, highlighting a high-value mix of magnet metals including dysprosium and terbium.
Large-scale HREE resource confirmed
The company reported an Inferred Mineral Resource of 122.5Mt at 889ppm TREO, containing 108,954 tonnes of total rare earth oxides, including 44,610 tonnes of heavy rare earth oxides (HREO) at a 300ppm cut-off.
Mount Ridley Heavy REE Topographic Location Map highlighting the MRE Zones
Notably, the resource carries a 41% HREO ratio, considered premium within global regolith-hosted systems, with 4,272 tonnes of dysprosium and 719 tonnes of terbium — both critical for high-performance permanent magnets used in electric vehicles and wind turbines.
The resource spans two main zones:
- Block 1 (Central Zone): 35.36Mt at 746ppm TREO
- Block 2 (Northern Zone): 87.18Mt at 947ppm TREO
High Priority Untested Gravity Ga-REE Target Zones
Multi-commodity system strengthens project economics
Mount Ridley said the rare earth mineralisation sits within the same regolith profile as its existing scandium and gallium resources, reinforcing the project’s potential as a multi-element critical minerals system.
CEO Allister Caird described the estimate as a “defining milestone,” highlighting the scale, shallow geometry and continuity of the deposit, alongside clear expansion potential through further drilling.
The deposit extends over more than 15.8km of strike and remains largely near surface, supporting potential bulk mining methods.
Growth upside and next steps
More than 80% of the project tenure remains untested, with multiple geophysical targets identified across a broader 1,000km² landholding.
Planned next steps include:
- Additional drilling to expand and upgrade the resource
- Metallurgical test work focused on HREE recovery
- Evaluation of processing pathways for combined REE, scandium and gallium production
Early test work has already indicated strong leach performance, with heavy rare earths showing favourable recovery characteristics relative to lighter elements.
Strategic positioning in critical minerals market
The announcement comes amid growing global demand for secure supplies of heavy rare earths, which remain heavily concentrated in Chinese and Southeast Asian supply chains.
Mount Ridley’s clay-hosted system — located near infrastructure and port access in WA — positions the company to potentially contribute to emerging Western-aligned critical minerals supply chains.
Regional Location Map showing the major Infrastructure such as Esperance Port, Road & Rail