Mount Ridley Mines (ASX: MRD) has announced a JORC 2012 Inferred Heavy Rare Earth (HREE) Mineral Resource of 122.54Mt at 889 ppm TREO (300 ppm cut-off) at its Mount Ridley Project.
This resource contains 108,954 tonnes of TREO and 44,610 tonnes of HREO.
The resource boasts a premium 41% HREO/TREO ratio.
It includes significant contained critical metals, specifically 4,272 tonnes of dysprosium (Dy2O3) and 719 tonnes of terbium (Tb4O7).
Shallow, Extensive Mineralisation
Mineralisation is described as shallow, extending from surface to 52m, and laterally extensive.
It spans a 15.8 km strike length across two blocks: Block 1 holds 35.36Mt at 746 ppm TREO, while Block 2 contains 87.18Mt at 947 ppm TREO.
The regolith-hosted deposit shows continuity and potential for bulk-tonnage open pit extraction.
Significantly, this heavy rare earth mineralisation occurs within the same regolith/clay system that hosts the company’s existing scandium and gallium resources, supporting a multi-critical minerals basket.
Exploration Upside and Future Plans
Mount Ridley Mines highlights that over 80% of its tenure remains untested, with multiple geophysical target corridors identified.
The company plans 2026 drilling and HREE resource definition.
The core near-term focus is delineation and upgrade of high heavy rare earth zones.
Metallurgical testwork to date indicates that HREE leach response is stronger than LREE, which could support preferential recovery of higher-value HREEs.
Context: Existing Resources
This new HREE resource builds on Mount Ridley Mines' existing critical minerals portfolio.
The company previously announced a maiden inferred scandium Mineral Resource Estimate (MRE) at Mount Ridley of approximately 368Mt at 57.3ppm Sc.
Additionally, a maiden gallium MRE for the Mount Ridley project stands at 838.7 million tonnes at 29.3 parts per million for 24,584t of contained gallium.
The company has also identified new rare earth element and gallium targets within its expanding Western Australia project area.
Outlook
Mount Ridley Mines has delivered a substantial JORC Inferred HREE resource, highlighted by its premium HREO/TREO ratio and significant contained dysprosium and terbium.
The shallow, extensive mineralisation and vast exploration potential position the project as a strategic critical minerals asset, with ongoing work expected to define higher confidence resources and advance development pathways.
