SMITHSONITE, ZnCO3 - Zinc Carbonate. Choice light green bohedreal crystals of Smithsonite on matrix. Specimen is 3.5 cm (1-3/8") wide by 2.3 cm (1-1/8") deep by 2.5 cm (1") high.Level 8, San Antonio El Grande Mine, San Antonio, Chihuahua, Mexico. No longer available.