Calcite

Potosí Mine, Santo Domingo (Francisco Portillo), Santa Eulalia District, Municipio Aquiles Serdán, Chihuahua  Mexico (±1994)

Specimen size: 14 × 10 × 3.5 cm = 5.51” × 3.94” × 1.38”
Main crystal size: 2.3 × 2.2 cm = 0.91” × 0.87”