
Three varieties of beryl: Morganite, Aquamarine, and Heliodor
The
mineral 'beryl' is a
beryllium aluminium cyclosilicate with the
chemical formula Be
3Al
2(
SiO3)
6. The
hexagonal crystals of beryl may be very small or range to several meters in size. 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 luster and can be transparent or translucent. Its cleavage is poor basal and its habit is dihexagonal bipyramidal. 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'' for the ''precious blue-green color of sea water''.
Varieties
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". Green beryl is called
emerald, red beryl is
bixbite or red emerald or scarlet emerald, blue beryl is
aquamarine, pink beryl is
morganite, colorless beryl is
goshenite, and a clear bright yellow beryl is called
golden beryl. Other shades such as yellow-green for
heliodor and honey yellow are common. 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) when exposed to sunlight will not fade in color.
Maxixe type beryl 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.
Deposits
Beryl is found most commonly in
granitic pegmatites, but also occurs in
mica schists in the
Ural Mountains and is often associated with
tin and
tungsten orebodies. Beryl is found in certain European countries such as
Austria,
Germany, and
Ireland. It also occurs in
Madagascar (especially morganite).
The most famous source of emeralds in the world is at Muzo and Chivor,
Boyacá,
Colombia, where they make a unique appearance in
limestone. Emeralds are also found in the
Transvaal,
South Africa,
Minas Gerais,
Brazil, and near
Mursinka in
Urals. In the
United States emeralds are found in
North Carolina.
New England's pegmatites have produced some of the largest beryls found, including one massive crystal 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. Other beryl locations include
South Dakota,
Colorado,
Utah,
Idaho, and
California.
As of 1999, the largest known crystal of any mineral in the world is a crystal of beryl from Madagascar, 18 metres long and 3.5 metres in diameter.
[1]
Applications
Massive beryl is a primary
ore of the metal
beryllium.
The
druids used beryl for
scrying, while the Scottish called them “stones of power”. The earliest crystal balls were made from beryl, later being replaced by rock crystal.
Synthetic beryl producer, including green
emerald, red, purple, "
Paraiba" color, etc.: Joint Venture
Tairus
References and external links
1. G. Cressey and I. F. Mercer, ''Crystals'', London, Natural History Museum, 1999
★ Sinkankas, John, 1994, ''Emerald & Other Beryls'', Geoscience Press, ISBN 0-8019-7114-4
★ Hurlbut, Cornelius S.; Klein, Cornelis, 1985, ''Manual of Mineralogy'', 20th ed., John Wiley and Sons, New York ISBN 0-471-80580-7
★
Minerals.net
★
Webmineral.com
★
Gems Explained
★
Mineral Galleries
See also
★
List of minerals