Occurring as massive or botryoidal forms, this mineral is an ore of manganese. Its name is derived from two Greek words meaning “smooth” and “black” in allusion to its appearance.
Occurring as massive or botryoidal forms, this mineral is an ore of manganese. Its name is derived from two Greek words meaning “smooth” and “black” in allusion to its appearance.
Mineral Photos courtesy of R.Weller/Cochise College