Chalcocite

Las Cruces Mine, Gerena-Guillena-Salteras, Comarca Sierra Norte, Seville, Andalusia  Spain

Specimen size: 2.2 × 1.6 × 0.4 cm = 0.87” × 0.63” × 0.16”
Main crystal size: 0.2 × 0.2 cm = 0.08” × 0.08”