Beryl is the chief ore of beryllium and includes gemstone varieties such as emerald and aquamarine.
Beryl is a cyclosilicate with the chemical formula Be₃Al₂Si₆O₁₈. Pure beryl is colorless, but trace elements create its familiar colors. Chromium or vanadium can produce green emerald, while iron commonly gives blue aquamarine.
Industrial beryl is an important source of beryllium, a light, stiff metal used in specialized aerospace components, X-ray equipment, and some instruments. Commercial beryllium is also obtained from minerals such as bertrandite.
Gem-quality beryl and ore-grade beryl are not interchangeable terms. Emerald is defined by its color and includes characteristic inclusions, while aquamarine is the blue to blue-green variety. Other beryl varieties include morganite, heliodor, and goshenite.