Adamite, (w. Tsumcorite and Philipsbornite)

Chemistry: Zn2(AsO4)(OH)
Size: 25 mm
Owner: Mariusz Oleszczuk
Photographer: Mariusz Oleszczuk

A fan of lustrous prismatic crystals of emerald-green adamite (?) is associated with a single tabular crystal of tan-coloured wulfenite (at right of photograph) and a crust of earthy yellow arsenate material.  A combination of XRD and EDS analysis has established that this yellow crust is a mixture of tsumcorite, philipsbornite, and quartz.

The adamite-olivenite series mineral has not been analysed, but the colour and habit are consistent with a composition in the adamite-zincolivenite range.