Acanthite

La Sirena Mine, 590 level, Guanajuato, Municipio Guanajuato  Mexico

Specimen size: 4 × 3.2 × 2.7 cm = 1.57” × 1.26” × 1.06”
Main crystal size: 1.2 × 0.8 cm = 0.47” × 0.31”