psilomelane
Noun
Meaning
A hydrous oxide of manganese, occurring in smooth, botryoidal forms, and massive, and having an iron-black or steel-gray color.
Source: Webster's dictionarySynonyms
chromite
ilmenite
limonite
galena
chalcopyrite
covellite
goethite
manganite
hematite
cassiterite
grossular
bornite
crocoite
andradite
hausmannite
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