Detailed information
Species
Braunite, Oyelite, Calcite
Dimensions
38 x 42 x 24
mm
Weight
20 g
Locality
N'Chwaning Mines Kuruman, Kalahari Mn. Field N. Cape Province, South Africa
Condition
No recorded repairs
You could say that this is a very black and white miniature specimen, but despite two species that are entirely contrasting in their colour both are very much rarities which display upon this piece remarkably fine crystals. Firstly, seeing as though it is from the N'Chwaning manganese mines, it is liberally covered on both sides in excellent tabular glossy black crystals of Braunite, a relatively rare manganese silicate oxide which is hardly ever well-crystallized. The crystals seen here are some of the best demonstrations of the tetragonal crystal form of Braunite and even though those on this piece are not as large as they can get, they are really very fine. On one side, contrasting with the black Braunite crystals is an 'island' of spiky acicular Oyelite crystals alongside which a grey-white rounded scalenohedral Calcite crystal lurks. Oyelite, a hydrated calcium silicate borate, is quite a rare species worldwide but the N'Chwaning manganese mines have also furnished some of the world's finest crystallized specimens, albeit they don't often sit associated with such fine Braunite crystals too. The identity of the finely crystallized cinnamon-coloured matrix is not certain, but might be Andradite garnet.