Beryl: an exceptional gemmy mineral species
The mineral species Beryl is an hexagonal beryllium-aluminium cyclosilicate, Be3Al2Si6O18. Cyclosilicates belong to the larger class of silicate minerals. Beryl is mostly a mineral typically found in coarse-grain plutonic crystalline rocks of granitic composition. The most important crystals are those related to pegmatites. Beryl is a favorite among mineral collectors because of its hexagonal gemmy crystals, various colours and hardness favorable to gemmology (Beryl is harder than Quartz).
Its name is possibly derived after the Greek word "beryllos" which referred to a number of blue-green stones in Antiquity. There are seventeen recognized varieties of Beryl, with Aquamarine (blue to sea-green), Emerald (green), Goshenite (colorless or white), Heliodor (golden yellow), Morganite (pink), and Red Beryl (often called Bixbite) being the most important ones to mineral collectors and gemmologists.
Aquamarine and Emerald have been known since Antiquity. Goshenite was originally described in 1844 from Barrus Farm locality, Goshen, Hampshire County, Massachusetts, United States. Heliodor was originally reported from both Hoffnungstrahl Pegmatite in 1912 near Rössing Station, Arandis, Arandis District, Erongo Region, Namibia and from Litchfield County, Connecticut, United States. Morganite was discovered in Madagascar at the beginning of the 20th century. Finally, Red Beryl was originally described from two localities: Maynard's Claim (Pismire Knolls) and The Cove, both in Thomas Range, Juab County, Utah, United States.
There are over five thousands known localities worldwide (currently 5742 reported localities on mindat.org) where Beryl has been identified. There are many excellent localities worldwide to find great Beryl specimens for their crystal size, perfection, gemminess and various colours. Currently, a large number of great specimens of interest to collectors are coming from Afghanistan, Brazil, China, Colombia, Madagascar, Namibia and Pakistan.
Collectors who wish to further investigate the geology and mineralogy of Beryl and find excellent photographs of this colourful mineral species are invited to consult the mindat.org website as well as the Mineralogical Record publications (especially volume 37, number 5, 2006 and volume 47, number 1, 2016).
Text published: January 2017.