This is a beautiful Sturmanite crystal from N’chwaning, Kalahari Manganese Field, Northern Cape, South Africa
Crystal Dimensions: 6.5cm (2.5”) x 2cm (0.7”)
Crystal Weight: 38.7 grams
Sturmanite is an uncommon mineral found in cavities within bedded manganese deposits that have been metamorphosed. It can be found only in South Africa where it finds its type locality at.
The Chemical formula for Sturmanite is: