Discovered in 1791 in the lavas of Mount Vesuvius, leucite is a rare mineral that can be found in recent potassium rich mafic and ultramafic lavas. It is found only in silica-deficient rocks and never in rock containing quartz. It is named from the Greek leucos for “white,” in allusion to its common color.

Mineral Photos courtesy of R.Weller/Cochise College