A grayish-white, hard, brittle, non-corrosive metallic element in the Group VIB of the Periodic System, obtained from chromite. One of the eight metallic elements, mainly responsible for green or red color in very important gem minerals such as emerald, ruby, spinel, pyrope garnet, demantoid garnet, jadeite, purple topaz, synthetic minerals, glassed, etc. Chemical symbol: Cr.