Garnet

Garnet is not a single mineral but a group of closely related silicate minerals that share the same crystal structure and differ in chemical composition. Five species are commercially important as gems: pyrope, almandine, spessartine, grossular and andradite; a sixth, uvarovite, usually forms crystals too small to cut. Many garnets are chemical mixtures of two or more species. Garnets occur in almost every color, and red garnet is one of the most common and widespread gems.