Chalcocite on Pyrite

Milpillas Mine, Cuitaca, Municipio Santa Cruz, Sonora  Mexico (2013)

Specimen size: 2.8 × 2.6 × 2.4 cm = 1.10” × 1.02” × 0.94”
Main crystal size: 1.8 × 0.9 cm = 0.71” × 0.35”