The Rosasite Group of Minerals

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The Rosasite Group is composed of minerals with either a monoclinic or triclinic symmetry and a general formula of A2(CO3)(OH)2. The A ion can be either cobalt, copper, magnesium, zinc and/or nickel. With color stimulating metals such as cobalt, copper and nickel common to this group, it is no real surprise that all these minerals are extremely colorful; usually green to blue. Unfortunately only rosasite is commonly found in mineral rock shops and kolwezite is scarcely available. The other members are rare to extremely rare.

MINERALS THAT BELONG TO THE ROSASITE GROUP:

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• Glaukosphaerite {Cu, Ni}2{CO3}{OH}2
• Kolwezite {Cu, Co}2{CO3}{OH}2
• Mcguinnessite {Mg, Cu}2{CO3}{OH}2
• Nullaginite Ni2{CO3}{OH}2
• Rosasite {Cu, Zn}2{CO3}{OH}2
• Zincrosasite {Zn, Cu}2{CO3}{OH}2

Malachite and other members of the Malachite Group are closely related to the Rosasite Group minerals.