Mariposite is not a recognized mineral but a chrome-rich variety of phengite, which is a silica-rich variety of muscovite, a mica.
Mariposite from Eureka District, Trigo Mountains, La Paz County, Arizona
Origin of name: named by American chemist and geologist Benjamin Silliman it´s type location: Mariposa County, California
Synonyms and trade names: chromphengite
Localities: mostly in the USA. Other locations are Canada, Venezuela, China, Japan, Egypt, Ireland, France and Spain. In Austria one deposit is known on the north slope of Brennkogel mountain in the High Tauern range.
Handling: due to the very low hardness and it´s perfect cleavage mariposite is not suited for use in jewellery