Anyolite is a
metamorphic rock
Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock ( protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, caus ...
composed of intergrown green
zoisite, black/dark green
pargasite
Pargasite or ''pargasitic hornblende'' is a complex Silicate mineral, inosilicate mineral of the amphibole group with formula NaCa2(Mg4Al)(Si6Al2)O22(OH)2.
It was first described for an occurrence in Pargas, Finland in 1814 and named for the loc ...
and
ruby
Ruby is a pinkish-red-to-blood-red-colored gemstone, a variety of the mineral corundum ( aluminium oxide). Ruby is one of the most popular traditional jewelry gems and is very durable. Other varieties of gem-quality corundum are called sapph ...
.
[http://www.mindat.org/min-27151.html Mindat] It has been found in the
Arusha Region
Arusha Region () is one of Tanzania's 31 administrative Regions of Tanzania, regions and is located in the northeast of the country. The region's capital and largest city is the city of Arusha. The region is bordered by Kajiado County and Narok C ...
of
Tanzania
Tanzania, officially the United Republic of Tanzania, is a country in East Africa within the African Great Lakes region. It is bordered by Uganda to the northwest; Kenya to the northeast; the Indian Ocean to the east; Mozambique and Malawi to t ...
and in Austria.
It is sometimes incorrectly advertised as a variety of the
mineral
In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2011): Mi ...
zoisite. The term ''anyolite'' is, however, not an officially accepted term for a metamorphic rock.
Its name derives from the
Maasai word ''anyoli'', meaning "green".
Anyolite is also referred to as ruby in zoisite, ruby zoisite, ruby-zoisite or Tanganyika artstone.
The contrasting colours make anyolite a popular material for sculptures and other decorative objects. It was first discovered at the
Mundarara Mine, near
Longido, Tanzania in 1954.
In 2010 it was suggested that a 2 kilogram stone known as the ''Gem of Tanzania'' owned by the defunct company
Wrekin Construction and fraudulently valued at £11 million was actually a lump of anyolite worth about £100,
although it was eventually sold for £8000.
It is reported that the stone originally came from a mine near
Arusha
Arusha is a city in Tanzania. The city is the Capital city, capital of the Arusha Region. It has a population of 617,631 people. , Tanzania.
References
External links
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Metamorphic rocks
Gemstones
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