Locality: Potosí Mine, Francisco Portillo, West Camp, Santa Eulalia Mining District, Aquiles Serdán Municipality, Chihuahua, Mexico
Size: 93 mm x 57 mm x 38 mm (3.7 in. x 2.2 in. x 1.5 in.)
Weight: 230 g (8.1 oz.)
A layer of small, translucent calcite crystals to ~1 mm and golden pyrite to 2 mm on galena matrix from a classic Mexican locality.