ASX-listed Viridis Mining and Minerals has defined a 200.6-million-ton maiden ore reserve at its Colossus project in Brazil, a figure the company says underpins a potential 40-year mine life and confirms the project’s tier-one status among global ionic clay rare earth deposits.

The all-probable reserve averages 2 640 parts per million (ppm) total rare earth oxides (TREO), including 740 ppm of magnet rare earth oxides (MREO) – the critical subset used in permanent magnets for electric vehicles and wind turbines. The estimate converts 61% of measured and indicated resources across the Northern Concession, Southern Complex and Capão da Onça deposits, while representing only 12% of Viridis’s broader landholding.

“The declaration of our maiden Joint Ore Reserve Committee reserve marks another important milestone for Viridis. To deliver 201-million tonnes at an outstanding 740 ppm MREO underscores both the scale and exceptional quality of Colossus,” MD Rafael Moreno said in a statement on Wednesday.

“Importantly, this Reserve covers only a fraction of our landholding, with high-grade zones like Tamoyo yet to be included, underscoring Colossus’ immense growth potential and strategic significance as a globally critical source of magnet rare earths.”

The company said the mine plan prioritises magnet rare earth elements such as neodymium, praseodymium, dysprosium and terbium to maximise product value. It is based exclusively on measured and indicated resources, with inferred material treated as waste.

Viridis added that the reserve more than doubles the scale of its February pre-feasibility study (PFS), which had assumed a 20-year life-of-mine from a 98.5-million-tonne base. “Our robust reserve base now underpins a potential mine life of up to 40 years, doubling the scale of our recent PFS, and provides the platform to establish Viridis as a long-term, tier-one supplier of the magnet rare earths critical to global decarbonisation and electrification,” Moreno said.

The Colossus project is located in Brazil’s Poços de Caldas Alkaline Complex, where Viridis has consolidated control over a 210-km² land package. Infrastructure includes paved road access and grid power, with the region already home to large-scale bauxite and alumina operations run by Alcoa and Companhia Brasileira de Alumínio.

Viridis is advancing Colossus toward a final investment decision, supported by partners including ORE Investments, Régia Capital, Brazil’s national development bank BNDES and the federal innovation agency FINEP.