Siegenite

This excellent miniature of the cobalt-nickel sulphide Siegenite is from Siegen in North Rhine-Westphalia, Germany, although not its exact type locality, as the names would imply.  The specimen is splendid in that as well as superb untarnished metallic-silver crystals of Siegenite, beneath the heavily oxidised sooty crust can be seen long well-formed arborescent fronds of Siegenite crystals to 2.5 to 3 cm long.  Where the Siegenite is untarnished, the modified cubic crystals form a porous crystalised band over an area of 6 x 2 cm, with individual crystals of up to 3 to 4 mm across.  This rich, well crystallised and dendritically structured specimen is from the Josef Clemente Collection of southern Germany.