Beryl

   
The mineral beryl is a beryllium aluminium cyclosilicate with the chemical formula Be₃Al₂(SiO₃)₆. The hexagonal crystals of beryl may be very small or range to several meters in size. Terminated crystals are relatively rare. Pure beryl is colorless, but it is frequently tinted by impurities; possible colors are green, blue, yellow, red, and white.

   Beryl of various colors is found most commonly in granitic pegmatites, but also occurs in mica schists in the Ural Mountains, and limestone in Colombia. Beryl is often associated with tin and tungsten ore bodies. Beryl is found in Europe in Norway, Austria, Germany, Sweden(especially morganite), and Ireland, as well as Brazil, Colombia, Madagascar, Russia, South Africa, the United States, and Zambia. U.S. beryl locations are in California, Colorado, Connecticut, Idaho, Maine, New Hampshire, North Carolina, South Dakota and Utah.

New England's pegmatites have produced some of the largest beryls found, including one massive crystal from the Bumpus Quarry in Albany, Maine with dimensions 5.5 m by 1.2 m (18 ft by 4 ft) with a mass of around 18 metric tons; it is New Hampshire's state mineral. As of 1999, the largest known crystal of any mineral in the world is a crystal of beryl from Madagascar, 18 meters long and 3.5 meters in diameter.

Golden beryl and heliodor

Golden beryl can range in colors from pale yellow to a brilliant gold. Unlike emerald, golden beryl has very few flaws. The term "golden beryl" is sometimes synonymous with heliodor (from Greek hēlios - ἥλιος "sun" + dōron - δῶρον "gift") but golden beryl refers to pure yellow or golden yellow shades, while heliodor refers to the greenish-yellow shades. The golden yellow color is attributed to Fe³⁺ ions. Both golden beryl and heliodor are used as gems. Probably the largest cut golden beryl is the flawless 2054 carat stone on display in the Hall of Gems,Washington, D.C.

Goshenite

Colorless beryl is called goshenite. The name originates from Goshen, Massachusetts where it was originally described. Since all these color varieties are caused by impurities and pure beryl is colorless, it might be tempting to assume that goshenite is the purest variety of beryl. However, there are several elements that can act as inhibitors to color in beryl and so this assumption may not always be true. The name goshenite has been said to be on its way to extinction and yet it is still commonly used in the gemstone markets. Goshenite is found to some extent in almost all beryl localities. In the past, goshenite was used for manufacturing eyeglasses and lenses owing to its transparency. Nowadays, it is most commonly used for gemstone purposes and also considered as a source of beryllium.

The gem value of goshenite is relatively low. However, goshenite can be colored yellow, green, pink, blue and in intermediate colors by irradiating it with high-energy particles. The resulting color depends on the content of Ca, Sc, Ti, V, Fe, and Co impurities.

Morganite

Morganite, also known as "pink beryl," "rose beryl," "pink emerald," and "cesian beryl," is a rare light pink to rose-colored gem-quality variety of beryl. Orange/yellow varieties of morganite can also be found, and color banding is common. It can be routinely heat treated to remove patches of yellow and is occasionally treated by irradiation to improve its color. The pink color of morganite is attributed to Mn²⁺ ions.

Discovery and naming

Pink beryl of fine color and good sizes was first discovered on an island on the coast of Madagascar in 1910. It was also known, with other gemstone minerals, such as tourmaline and kunzite, at Pala, California. In December 1910,the New York Academy of Sciences named the pink variety of beryl "morganite" after financier J. P. Morgan.

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