Beryl

The mineral beryl is a silicate of beryllium and aluminium with the chemical formula Be₃Al₂(SiO₃)₆. The hexagonal crystals of beryl may be very small or range up to a meter in length and diameter. Terminated crystals are relatively rare. Beryl exhibits conchoidal fracture, has a hardness of 7.5-8, a specific gravity of 2.63-2.80. It has a vitreous lustre and can be transparent or translucent. Pure beryl is colorless, but it is frequently tinted by impurities; possible colors are green, blue, yellow, red, and white.

Beryl has been considered a gemstone since prehistoric times. Green beryl is called emerald, blue beryl is aquamarine, pink beryl is morganite, and a clear bright yellow beryl is called golden beryl. Other shades such as yellow-green and honey yellow are common.

Beryl is gound in granite rock and especially in pegmatites, but also occurs in mica schists in the Ural mountains. In addition to many European locations such as Austria, Germany, Ireland, etc., beryls are also found in Africa, Madegascar (espeically for morganite), and Brazil. The most famous source of emeralds in the world is at Muso Colombia, where they make a unique appearance in limestone. Emeralds are also found in the Transvaal and near Mursinski in Siberia. New England's pegmatites have produced some of the largest beryls found, including one 18 feet long and 4 feet across that weighed 18 tons. Other locations include Paris, South Dakota, Colorado, and California.

Metallic beryllium is obtained from beryl. The word beryl comes from the Greek.

Further Reading

• Emerald & Other Beryls, John Sinkankas, Geoscience Press, 1994, hardcover textbook, ISBN 0801971144