5FT86: Two generations of Calcite. The first generation is stalactitic Calcite, while in the second generation the Calcite takes the more classic crystalline form for the locality. Crystals of both generations have good luster, and both appear partially colored by brown iron oxides. A very decorative piece originating in the Cretaceous carbonate strata of the Sierra de Santa Eulalia.
Santa Eulalia District, Municipio Aquiles Serdán, Chihuahua  Mexico (1988)

Specimen size: 13.5 × 9 × 7.8 cm = 5.31”