Calcite is one of the most amazing and collectible minerals because of the huge array of crystal habits it shows off. This sharp crystal is a highly modified rhombohedron, and a rare style and shape from Mexico. It was in Alex Schauss's large calcite suite because he collected such suites not based on overall value, but to make educational assemblies of crystals that complemented and informed on each other by doing so. The habit is really special. It does have damage and edge wear, however.