Beryl Gemstones: Emerald, Aquamarine, Golden Beryl and Morganite
The beryl species is one of the most notable gemstone families. Many people are acquainted only with the most famous beryl - emerald. But the beryl family includes several other important gemstones, including aquamarine, morganite, golden beryl and bixbite.
All beryl gemstones are aluminum beryllium silicates, and have a hardness of 7.5 to 8 on the Mohs scale. The different varieties of beryl are distinguished by their color, and they differ significantly in their transparency and clarity.
Surprisingly, the most valuable beryl, emerald, tends to have the most inclusions and the least transparency. But emerald is famous for its incomparable color, which is due to traces of chromium. Columbia is most famous source for emerald, but important deposits are also found in Brazil, Zimbabwe, Afghanistan, Madagascar, Nigeria, Tanzania and Zambia.
The second most famous beryl is aquamarine, named for its seawater-like color. Aquamarine is colored by traces of iron. The deepest colors are valued most highly, though many of the darker colored emeralds on the market have been improved by heat treatment. The traditional source for aquamarine is Brazil, but recently some very fine Mozambique material has made an appearance.
All of the other beryls are known as precious beryl, but the pink variety has been given the name morganite, in honor of the American banker and gemstone collector, J.P. Morgan. Morganite is usually a soft pink to violet, but a salmon-color is also known. The best known morganite deposits are in Afghanistan.
Golden beryl, occurring in lemon-yellow and golden-yellow, tends to have exceptionally good clarity. Inclusions are rare in golden beryl, and the superb clarity combined with the fine color make this beryl an excellent stone for all kinds of jewelry. Golden beryl is found in Brazil, Madagascar, Namibia, Nigeria, Sri Lanka and Zimbabwe.
There are several other fairly rare varieties of beryl. The raspberry-red variety is often sold under the name bixbite. It is quite rare, and to date it has been found only in the state of Utah in the USA. Colorless beryl is called goshenite after a deposit in Goshen, Massachusetts.
Finally, it's worth noting that the gemstone chrysoberyl is not, despite its name, a member of the beryl family. Chrysoberyl has a different chemical composition (beryllium aluminum oxide) and a hardness of 8.5 on the Mohs scale. Chrysoberyl can appear quite similar to golden beryl. The most famous chrysoberyl is alexandrite.
- Впервые опубликовано: February-08-2008
- Последняя редакция: November-07-2017
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