ˌstilpnōˈmeˌlān noun
( -s )
Etymology: German stilpnomelan, from Greek stilpnos glistening + melan-, melas black — more at : stilbum , mullet
: a black or greenish black mineral K(Fe,Al) 10 Si 12 O 30 (O,OH) 12 (?) occurring in foliated plates, fibrous forms, and velvety bronze-colored incrustations and consisting of a hydrous iron aluminum silicate with a little potassium (sp. gr. 2.77-2.96)