Lópezite

Lopezite is a rare red chromate mineral with chemical formula: K₂Cr₂O₇. It crystallizes in the triclinic crystal system.

It occurs as rare vug fillings in nitrate ores in association with tarapacáite (K₂CrO₄), dietzeite and ulexite in the Chilean Atacama and is reported from the Bushveld igneous complex of South Africa. Lopezite was first described in 1937 for an occurrence in Iquique Province, Chile and named for Chilean mining engineer Emiliano López Saa (1871–1959).