stilpnomelane
noun
stilp·no·mel·ane
| \ ˌstilpnōˈmeˌlān\
plural -s
Definition of stilpnomelane
: a black or greenish black mineral K(Fe,Al)10Si12O30(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 (specific gravity 2.77–2.96)
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