( n. )
A black or greenish black mineral occurring in foliated flates, also in velvety bronze-colored incrustations. It is a hydrous silicate of iron and alumina.
( n. )
A black or greenish black mineral occurring in foliated flates, also in velvety bronze-colored incrustations. It is a hydrous silicate of iron and alumina.
Webster's Revised Unabridged English Dictionary. Пересмотренный полный словарь английского языка Webster. 2012