Detailed information
Species
Hausmannite, Andradite
Dimensions
65 x 98 x 43
mm
Weight
328 g
Locality
N'Chwaning Mines Kuruman, Kalahari Mn. Field N. Cape Province, South Africa
Condition
No recorded repairs
Despite Hausmannite’s deceptively simple chemical formula, it is a complex manganese oxide containing both divalent (Mn2+) and trivalent (Mn3+) manganese. This spectacular example is from the N'Chwaning Mines at Kuruman in Northern Cape Province, South Africa, one of the mines within the Kalahari Manganese Field. Semi-lustrous, black Hausmannite crystals cover at least fifty percent of the display face of a rich, salmon pink Andradite garnet matrix, in the form of sub-millimetre crystals giving the matrix a fine-granular texture. The Hausmannite forms as stepped octahedral crystals built from small, individual tetrahedral prisms, each with a sub-metallic lustre and rough, pitted surface texture. With the magnificent Hausmannite crystals contrasting nicely against the orangey pink Andradite, this makes a superb cabinet specimen of museum quality.
