Calcite is a very common and widespread mineral with many forms and colors. Found in most geologic settings in one form or another, it is most common as massive material in limestones and marbles. Because calcite is relatively soft and fragile, it is not usually an important gem mineral. This calcite gem from Balmat, New York, is a spectacular display piece and a testament to the gem cutter's art, in this case that of Art Grant. At 1,865 carats, it is also probably the largest and finest faceted calcite in the world.