Chemistry: Zn2(AsO4)(OH)
Size: 65 mm
Owner: Mariusz Oleszczuk
Photographer: Mariusz Oleszczuk

Aggregates of bladed, yellow adamite crystals (to 9 mm; XRD verified) associated with colourless-white sheaves of smithsonite (to c. 3 mm) on a thin, yellow-orange rind of tsumcorite (XRD confirmed).  The matrix is massive chalcocite.

Although the composition of the adamite has not been determined, the colour suggests that it contains very little copper and that it is therefore close in composition to the zinc-rich end-member of the adamite-olivenite series.

The specimen was formerly in the collections of noted British collectors Richard Barstow and Keith Hammond (see labels).