The finest crystals of pyrrhotite and cubanite in southern Africa were recently discovered at one of the deepest mines in the world, the Mponeng mine, situated in the Witwatersrand goldfield in South Africa. Coincidentally, huge barite crystals, more than 50 cm, were also found at a neighboring mine. Aesthetic specimens of galena, sphalerite, quartz, and calcite occur as well.
The Witwatersrand goldfield is the largest deposit of gold on Earth, dwarfing all others (Frimmel 2002). ...