Wiktionary
calumetite
n. (context mineral English) An orthorhombic mineral containing chlorine, copper, hydrogen, and oxygen.
Wikipedia
Calumetite
Calumetite is a natural rarely occurring mineral. It was discovered in 1963 at the Centennial Mine near Calumet, Michigan, United States. Calumetite was first discovered along with anthonyite. It has a chemical formula of Cu(OH,Cl)•2(HO).