Mariposite is a green chromium-bearing variety of phengite, first described in 1868 from the Mother Lode country of California, where it is associated with gold-bearing quartz veins and serpentinite precursors. It generally is massive in habit, with a waxy luster and no visible crystals. Mariposite-bearing quartz rock is a popular landscaping stone, itself often called mariposite. The name comes from Mariposa County. Supposedly the rock was once a candidate for the California state rock, but serpentinite prevailed.