'Aquamarine' (Lat. ''aqua marinā'', "water of the sea") is a
gemstone-quality transparent variety of
beryl, having a delicate blue or turquoise color, suggestive of the tint of
seawater. It's closely related to the gem
emerald. Colors vary and yellow beryl, called ''
heliodor''; rose pink beryl, ''
morganite''; and white beryl, ''
goshenite'' are known.
Aquamarine is a beryl with a
hexagonal crystal structure and a
chemical formula of Be
3Al
2Si
6O
18, a
beryllium aluminium silicate mineral. It has a
specific gravity of 2.68 to 2.74 and a
Mohs hardness of from 7.5 to 8. Aquamarine typically is on the low end of the specific gravity range, normally at less than 2.7. The pink variety exhibits a high specific gravity of around 2.8.
Refractive indices range around 1.57 to 1.58.
It occurs at most localities which yield ordinary beryl, some of the finest coming from
Russia. The gem-gravel
placer deposits of
Sri Lanka contain aquamarine. Clear yellow beryl, such as occurs in
Brazil, is sometimes called aquamarine chrysolite. When
corundum presents the bluish tint of typical aquamarine, it is often termed Oriental aquamarine.
In the
United States, aquamarines can be found at the summit of
Mt. Antero in the
Sawatch Range in central
Colorado. In
Brazil, there are mines in the states of
Minas Gerais,
Espírito Santo and
Bahia. Zambia also produces nice aquamarine as well as Madagascar, Malawi, Tanzania and Kenya. Much of today's aquamarine is heated to give it a better color blue. The deeper the blue color, the more valuable the gem is considered.
The biggest aquamarine ever mined was found at the city of Marambaia, Minas Gerais, Brazil, in 1910. It weighed over 110 kg, and its dimensions were 48.5 cm long and 42 cm in diameter.
Aquamarine is the
official state gem of Colorado.
Culture and historical/mythical usage
★ Aquamarine (along with Bloodstone) is the
birthstone associated with March. It is also the gemstone for the 19th Anniversary.
★ People in the
Middle Ages thought that aquamarine could magically overcome the effects of
poison.
★ Ancient sailors traveled with aquamarine crystals, believing that it would ensure a safe passage, and often slept with the stones under their pillow to ensure sound sleep. They believed the siren’s (
mermaid) fish-like lower body was made of aquamarine.
See also
★
List of minerals
References
1. Gemological Institute of America, ''GIA Gem Reference Guide'' 1995, ISBN:0-87311-019-6
★ Weinstein, Michael, 1958, ''The World of Jewel Stones'' Sheriden House, New York, pp 104-107
★ Diamond Bug.
"Flawless Aquamarine: March Birthstone". Retrieved March 16, 2006.
★ http://www.gemstone.org/gem-by-gem/english/aquamarine.html
★ http://mineral.galleries.com/minerals/gemstone/aquamari/aquamari.htm
★ http://www.mindat.org/min-289.html