Mimetite, whose name derives from the Greek which means “imitator” is not really like any other mineral I’ve seen. It’s basically a lead arsenate chloride mineral which forms as a secondary product in lead deposits.
It has no major uses, being a minor ore of lead, being usually gathered by collectors. It’s not used as a gemstone because of its softness. Alternative names of mimetite include arsenopyromorphite, mimetesite, and prixite.