Rhodochrosite (Pseudomorph after Calcite) from Greece
“This beautiful specimen is an extraordinary example of pseudomorphosis, wherein the original mineral (calcite) left its distinct crystal form and was replaced by a new mineral, the pink rhodochrosite. Thus, this specimen illustrates the typical characteristics of rhodochrosite—pink color, a greater hardness and weight than calcite, and a chemical composition primarily composed of manganese—but it will retain forever the original form of its calcite host. It was coated lightly at a later time in its history by a light crust of tiny colorless quartz crystals. There are a number of small pyrite crystals down one side of the matrix”.