THE MINERAL KOLWEZITE

Chemistry: (Cu, Co)2CO3(OH)2, Copper Cobalt Carbonate Hydroxide.
Class: Carbonate
Group: Rosasite
Uses: A very minor ore of copper and cobalt, and as mineral specimens.
Specimens

Kolwezite is a rare mineral that is a similar mineral to the much more common and well-known mineral malachite. Malachite's formula is Cu2CO3(OH)2. Kolwezite contains a significant percentage of cobalt in place of some of the copper in malachite.

Cobalt and copper are two very strong coloring agents. Unfortunately, kolwezite is perhaps too strongly colored and is commonly black. It was only identified in the past fifteen years making it a rather "young" mineral in the mineral world. It is named for the famous mines at Kolwezi, Shaba, Zaire from where it was first discovered and from where many new and rare minerals are found.

PHYSICAL CHARACTERISTICS:

Color is black, green to brown.
Luster is
Transparency is translucent.
Crystal System is triclinic; bar 1
Crystal Habits include prismatic to acicular crystal sprays and crusts.
Hardness is 4.
Specific Gravity is 4.0 (slightly heavy)
Associated Minerals include malachite, siderite, cobaltian calcite and sphaerocobaltite.
Notable Occurrences are limited to Kolwezi area of Shaba, Zaire.
Best Field Indicators are color, locality, density and hardness.