Lopezite

Lopezite is a rare red chromate mineral with chemical formula: K₂Cr₂O₇. It crystallizes in the triclinic crystal system.[1][2]

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.[1][2] Lopezite was first described in 1937 for an occurrence in Iquique Province, Chile and named for Chilean mining engineer Emiliano López Saa (1871-1959).[1]

Most lopezite offered for sale to collectors is artificially produced.[1] Synthetic varieties also exhibit monoclinic crystals.[3]

References

1. ^ a b c d http://www.mindat.org/min-2433.html Mindat
2. ^ a b http://rruff.geo.arizona.edu/doclib/hom/lopezite.pdf Handbook of Mineralogy
3. ^ Richard V. Gaines, H. Catherine W. Skinner, Eugene E. Foord, Brian Mason, and Abraham Rosenzweig: "Dana's new mineralogy", p. 692. John Wiley & Sons, 1997

List of minerals