Galena

tennantite subgroup

Intergrown crystals of galena (to 16 mm) with an essentially cubic habit comprising dominant {100), with (possibly) minor {111} and {110} partly obscured by the rounding of the crystals. There is a little matrix material on the reverse side of the specimen that appears to consist largely of tennantite subgroup - probably tennantite-(Zn) (?).

The galena crystals have an etched appearance with fine striations typical of idiomorphic galena at Tsumeb and possibly related to stress-induced twinning (Ramdohr 1980). 

The specimen is in the collection of Sharon and Eugene Cisneros but belonged formerly to Tsumeb baker Toni Pietsch.