Galena, (w. Quartz)

Mineral: Galena, Quartz
Chemistry: PbS
Size: 73 mm
Owner: Mariusz Oleszczuk
Photographer: Mariusz Oleszczuk

A stalactite-like aggregate of crystallised galena decorated, on one side of the specimen, with crystals of colourless to milky-white quartz.

At least some of the galena crystals appear to be spinel-law twins, and all are heavily striated which may be the result of mechanically induced "glide twinning" (see Ramdohr, 1980).