Mineral Species: Rosasite and Malachite

Chemical Formula: (Cu,Zn)2CO3(OH)2

Chemical Name: Copper Zinc Carbonate Hydroxide

Mineral Class: Carbonate

Mineral Notes:  Rosasite forms in the oxidation zones of mixed copper/zinc deposits. It is ususally found as crusts and botryoidal masses or nodules. Crystals are fibrous and found in tufted aggregates. The colour is an attractive blue green. For this reason the mineral can be confused with Aurichalcite. However Rosasite is usually more massive but not lamellar. Rosasite crystals are also significantly harder than Aurichalcite.

Description: A brown matrix hosting a blue crust of Rosasite. Under magnification individual crystals can be seen. Next to the Rosasite is an extraordinary occurrence of green Malachite. The mineral has crystallised to form three spherical nodules. Two of these are twinned. A really great combination.

Location: Kozari-Kofejlo, Hungary.