The mineral beryl is a beryllium aluminium cyclosilicate and the hexagonal crystals of beryl may be very small or range to several meters in size. It has a vitreous luster 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. The name comes from the Greek beryllos which referred to a precious blue-green color of sea water stone. The term was later adopted for the mineral beryl more exclusively.
Varieties of beryl have been considered gemstones since prehistoric times. Recognized for its beauty, in the Bible, in Ezekiel 1:16, the wheels of God’s throne are described as having the appearance of “gleaming beryl.”
Colorless beryl is called goshenite, pink beryl is morganite, red beryl is bixbite or “red emerald” or “scarlet emerald,” clear bright yellow beryl is “golden beryl,” yellow-green beryl is heliodor, green beryl is emerald, blue beryl is aquamarine, and deep blue beryl is maxixe. Red beryl is extremely rare and is not used in jewelry as the crystals it forms are very small; it is mined primarily in Utah. Blue beryl (aquamarine) will not fade in color when exposed to sunlight. Maxixe is a deep blue stone that fades to white when exposed to sunlight or is subjected to heat treatment, though the color returns with irradiation. Other, unnamed shades such as honey yellow are also known.