|
|
www.mineralgallery.co.za Minerals F-J |
|
|
Gaudefroyite |
||
Name
Gaudefroyite
Chemistry
Ca4Mn3 [3(BO3)3(CO3)(O,OH)3]
Uses
As a collectors specimen
Color
Black to charcoal and bronze
Streak
White
Crystals
It forms prysmatic needle-like crystals
Accompanied by:
Manganite, hausmannite, gypsum, calcite, hematite and barite
Similar to:
Stibnite
Here in the Kalahari Manganese field gaudefroyite of up to 5 cm's were found at the N'Cwaning II mine in 1995. The biggest of this scarce mineral ever found in the world. They also took out needle-like crystals that occured as matted aggregates. These were often associated with yellow ettringite, small silver hematite crystals and hausmannite.
Fine crystalline anhedral gaudefroyite is quite common as a minor constituent of high-grade Wessels type ore at N'Chwaning I and II and Wessels mines.
