Anyolite

Although anyolite is advertised as a variety of the mineral zoisite from Kenya and the Arusha Region of Tanzania, anyolite is actually a metamorphic rock composed of intergrown green zoisite, black/dark green pargasite (erroneously identified as tschermakite), and ruby.[1][2] The term anyolite is however not an officially accepted term for a metamorphic rock.[3] It is said to be named after the Maasai word anyoli, meaning "green." Anyolite is also referred to as ruby in zoisite or Tanganyika artstone.

An unpolished sample of anyolite, also known as "ruby in zoisite".

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,[4] although it was eventually sold for £8000.[5] It is reported that the stone originally came from a mine near Arusha, Tanzania[6]

References

  1. http://www.mindat.org/min-27151.html Mindat
  2. http://www.cst.cmich.edu/users/dietr1rv/zoisite.htm Gemrocks
  3. Metamorphic rocks, A classification and glossary of terms, D. Fettes and J. Desmons ed., Cambridge University Press
  4. Jonathan Guthrie (October 1, 2009). "Now £11m Gem of Tanzania hits rock bottom". Financial Times.
  5. "Wrekin's '£11m' Gem of Tanzania ruby sold for £8k". BBC News. 16 February 2010.
  6. Guthrie, Jonathan; Pearson, Samantha (27 March 2019). "The strange journey of the 'jinxed' jewel". Financial Times. Retrieved 18 September 2019.


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