Background of Cobaltoan-Calcite xx
It is a variety of Calcite containing Cobalt. The cobaltoan calcite comes from the Mashamba West Mine near Kolwezi in the Shaba copper belt in the Democratic Republic of Congo. Shaba is the region formerly known as Katanga, the former Zaire in central Africa. The Mashamba West Mine is an opencast mine which started in 1878 and is situated in the western sector of the Shaba copper belt and extended within the zone that is geologically called the “cliff of Kolwezi” from the west of the Lualaba river to 20km outside the town Kolwezi.
Some of the best pieces of pink cobaltoan-calcite are found here. Some were with crystals up to 2 cm size. Cobalt, which causes the magenta to pale-pink color of cobaltoan-calcite appears only as a trace element with content of at most about 1%. As crystal forms appear rhomboedrons as well a mixing form between rhomboedera, scalenohedrons and sometimes prisms.
The cobaltoan-calcite is not a cheap mineral. It is rather rare to find and the ones with nice crystal forms cost over thousands of dollars for a small piece.
The specimen is about 2.25 x 1.5 inches. Including the display box, it weights 2.7 oz. The color is bright pink or magenta. The crystals are like some ripe Pomegranate, each with its own facets.