Locality: Cerro de Pasco, Pasco Province, Pasco Department, Peru
Size: 73 mm x 55 mm x 14 mm (2.9 in. x 2.1 in. x 0.5 mm)
Weight: 65 g (2.3 oz.)
Dark, lustrous bournonite crystals to 4 mm, with just a few of them twinned in a characteristic cogwheel pattern, on a plate of matrix with clear and translucent quartzto 2 mm. A small amount of pyrite adds shine to this specimen. Bournonite and quartz on the bottom of the piece as well.