Lustrous sharp black octahedral crystals of jacobsite across a calcite crystalline matrix. This is very good for the species. In good condition.
The N'chwaning III Mine, situated within the renowned Kalahari Manganese Field in the Northern Cape of South Africa, represents one of the world's richest and most scientifically significant manganese deposits, with mining operations expanding significantly in the latter half of the twentieth century. Geologically, the deposit is hosted within the Paleoproterozoic Hotazel Formation of the Transvaal Supergroup, where extensive chemical sedimentation and subsequent hydrothermal alteration created unique manganese-rich ore bodies. Mineralogically, the mine is celebrated worldwide for producing exceptional specimens of jacobsite, a dense manganese-iron oxide mineral belonging to the spinel group, which forms sharp, lustrous, metallic black octahedral crystals with calcite.
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