The top and sides of this matrix are covered with blue lustrous small bladed crystals of manganite. This is in good condition. The specimen comes with a previous label from the collection of Ray DeMark.Located in the Kalahari Manganese Field of the Northern Cape in South Africa, the Black Rock Mine exploits one of the largest and most concentrated sedimentary manganese deposits in the world, with commercial mining operations expanding significantly since the mid-twentieth century. The deposit is hosted within ancient sedimentary sequences that experienced extensive geological alteration over immense spans of time. Among the notable mineral species recovered from these massive ore bodies is manganite, which occurs here as brilliant, well-crystallized prismatic crystal groups associated with other manganese minerals, making the locality world-renowned for producing exceptional collector specimens.
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