Jade is either of two tough, compact, typically green gemstones that take a high polish. Both minerals have been carved into jewelry, ornaments, small sculptures, and utilitarian objects from earliest recorded times. The more highly prized of the two jadestones is jadeite; the other is nephrite. Jadeite and nephrite differ in both chemical composition and crystalline structure. Jadeite is a silicate of sodium and aluminum and is classed as a pyroxene.

Source: Britannica