Chalcocite

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

Specimen size: 3.1 × 2.1 × 0.7 cm = 1.22” × 0.83” × 0.28”
Main crystal size: 0.4 × 0.2 cm = 0.16” × 0.08”