Beryl

Beryl, beryllium and aluminum silicate (Be₃AP₂Si₆O₁₈), the most common ore of beryllium. It is a transparent or translucent mineral found mainly as hexagonal crystals in granite rocks. The gem emerald is a dark green beryl containing a small amount of chromium; aquamarine is a blue-green variety of beryl. The finest varieties are found in Brazil, Sri Lanka, Siberia, and New England.

See also: Aquamarine; Beryllium.