Chemistry: Cu3(CO3)2(OH)2
Size: 75 mm
Owner: Mariusz Oleszczuk
Photographer: Mariusz Oleszczuk

Equant crystals of lustrous, deep royal-blue azurite (to 10 mm) on a reddish-brown druse of tsumcorite (XRD and EDS analysed), over smithsonite crystals.  The matrix (not visible in this photograph) consists of unidentified yellow and green copper/lead secondaries.

EDS analysis of the tsumcorite group mineral showed some degree of iron substitution which, together with the red-brown colour, suggests, perhaps, a composition somewhere between tsumcorite and mawbyite (?). 

The specimen was formerly in the collection of Franz Lammer (Austria).