Ionic-clay rare-earth deposits form through intense tropical weathering of granitic or alkaline basement rocks. Rare earths are loosely bound to clay minerals and can be released by gentle leaching — no high-temperature cracking, no aggressive acid bake, no sulphuric-acid roaster. Processing is mechanically simpler and has a lower environmental footprint than bastnaesite.
Critically, ionic clays carry a meaningful proportion of heavy rare earths — dysprosium and terbium — compared to most bastnaesite deposits. This aligns with what permanent-magnet manufacturers actually need. China's Jiangxi province is the world's dominant ionic-clay producer; Brazil's Goiás and Minas Gerais are now building the Western equivalent.
Most Western rare-earth production comes from carbonatite-hosted deposits: MP Materials' Mountain Pass (California), Lynas's Mt Weld (Australia), and Brazil's Alto Paranaíba complexes. Bastnaesite requires a high-temperature sulphuric-acid bake to release the rare earths — more energy-intensive and chemically aggressive than ionic clay. Generally richer in light rare earths (neodymium, praseodymium, cerium, lanthanum).
The Alto Paranaíba Igneous Province spans Minas Gerais and Goiás, hosting Araxá, Catalão and related alkaline-carbonatite complexes. CBMM's niobium operation at Araxá has rare-earth content as a persistent co-product. Serra Negra, Salitre I-II-III, Tapira and Ouvidor are additional intrusive complexes with rare-earth potential. The province has hosted continuous industrial mining for over 50 years.
Pela Ema sits on the Minaçu-Niquelândia axis in northern Goiás. Deep tropical weathering over granitic basement has produced ionic-clay enrichment with a meaningful heavy-rare-earth distribution. Total TREO content is modest by carbonatite standards, but the element distribution — including dysprosium and terbium — and the simple processing chemistry give it competitive economics.
JORD is a large alkaline system in Frontera Minerals' portfolio: more than 1.5 km × 1.5 km surface extent, grades above 2,500 ppm TREO, with optional niobium credits. Alkaline-hosted rare-earth systems at this scale are geologically significant — large footprint implies large potential tonnage.