Chalcocite

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

Specimen size: 2.8 × 1.9 × 0.3 cm = 1.10” × 0.75” × 0.12”
Main crystal size: 0.3 × 0.2 cm = 0.12” × 0.08”