Azurite, (w. Aragonite and Conichalcite)

Chemistry: Cu3(CO3)2(OH)2
Size: 60 mm
Owner: Mariusz Oleszczuk
Photographer: Mariusz Oleszczuk

A single perfect, terminated prismatic crystal of blue-black azurite (c. 20 mm) is associated with blocky off-white crystals of aragonite (var. tarnowitzite), on a carbonate matrix that is partly encrusted with a druse of conichalcite (XRD verified).

This is a somewhat unusual association of minerals.