chalcophanite
noun
chal·coph·a·nite
kalˈkäfəˌnīt
plural -s
: a mineral (Zn,Mn,Fe)Mn2O5.nH2O consisting of black hydrous manganese and zinc oxide and having a metallic luster
Word History
Etymology
chalc- + phan- (from Greek phainein to show) + -ite; from its change to a copper color when heated