Highlights

• Meteoric Resources' Caldera project in Brazil contains ~1.5 billion tonnes at ~2,300 ppm of ionic clay rare earths, with early mining zones at ~4,000 ppm based on only 20% exploration.
• The project features a simplified extraction process from weathered volcanic clay, targeting 13,500 tpa rare earth oxide equivalent production by 2028 with $450M capex investment.
• Caldera represents a strategic ex-China heavy rare earth source producing mixed rare earth carbonate, though success depends on securing financing and downstream separation partnerships.

In a recent Rare Earth Exchanges podcast (opens in a new tab), Andy Thomson (opens in a new tab), CFO of Meteoric Resources, outlined one of the more compelling emerging rare earth opportunities outside China: the Caldera project in Brazil’s Minas Gerais. Located within an extinct volcanic system, the deposit has weathered into ionic adsorption clay, a rare geological format that enables simpler, lower-cost extraction of rare earth elements—including critical heavy rare earths—without drilling, blasting, or complex crushing.

A Tier-One Asset Taking Shape

The scale is significant. Meteoric has defined ~1.5 billion tonnes at ~2,300 ppm, with early mining zones targeting ~4,000 ppm, based on only ~20% of the land package explored. The contained caldera structure helps limit lateral dispersion, supporting grade continuity. The company positions Caldera as a multi-decade, potentially multi-generational resource with scalability still largely untested.

Development Path and Timeline

The project has progressed through a pre-feasibility study (PFS) and is advancing a definitive feasibility study (DFS) alongside Brazil’s staged permitting process. An on-site pilot plant is producing mixed rare earth carbonate (MREC), validating processing assumptions and supporting offtake discussions. The base case targets ~13,500 tonnes per annum of total rare-earth oxides-equivalent output from a ~6 Mtpa operation, with a 2028 production target, subject to financing and final approvals.

Strategic Opportunity—and Constraints

Caldera’s ionic clay profile—similar to that of southern China and Myanmar—places it among a limited set of credible ex-China heavy rare-earth feedstock projects. However, initial production is expected at the MREC stage, with separation, metallization, and magnet production handled by downstream partners.

Key risks remain: ~$450 million capex, execution timelines, and dependence on non-Chinese separation capacity. Still, if realized, Caldera could become a foundational upstream asset in an emerging Western-aligned rare earth supply chain.