Aquamarine

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This article is about the mineral. For other uses of the term, see Aquamarine (disambiguation).

Aquamarine (Lat. aqua marina, "water of the sea") is a gemstone-quality transparent variety of beryl, having a delicate blue or blue-green 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 Be₃Al₂Si₆O₁₈, 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 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 mineral of Colorado.

Culture and historical/mythical usage

Aquamarine 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.