Enstatite is one of the pyroxene families - a series of magnesium- to iron-rich silicates. (Crystals occur as short prisms, but are rare: most gem-quality material is faceted from rolled pebbles, Cut table institute varies in color from a grey- to yellowish green or olive-green, to an iron-rich brownish green. A brilliant emerald-green variety, coloured by chromium, also occurs.

Enstatite is often found with kimberlites in South Africa. Brownish green enstatite is found in Burma, Norway, and California (USA). Some Sri Lankan and Indian enstatite is chatoyant, It also occurs in the USA, Switzerland, Greenland, Scotland, Japan, and the former USSR.

Most emerald used in historical jewellery would have been from Cleopatra's mines in Egypt's, which now yield only poor-quality emeralds.