Calcite

An old time piece from the famed locality of the classic “butterfly twin” form which came out at least 25 years ago and are typically comprised of several stages of growth. It takes some close examination to realize just how good this piece is.  The initial growth scalenohedrons included the red to brown clay in which it was forming. The crystals completed with glassy clear surfaces in many areas, but other areas continued to evolve with inclusions of the surrounding clay. The surfaces then began to grow secondary crystals on the select surfaces, further compounding the complexity of growth features. Fantastic specimen in excellent condition!

Locality: Santa Eulalia, Aquiles Serdan. Chiguahua, Mexico

Composition: calcium carbonate