Anyolite is a metamorphic rock composed of intergrown green zoisite, black/dark green pargasite and ruby.[1] It has been found in the Arusha Region of Tanzania and in Austria.[1] It is sometimes incorrectly advertised as a variety of the mineral zoisite. The term anyolite is, however, not an officially accepted term for a metamorphic rock.[2] Its name derives from the Maasai word anyoli, meaning "green".[1] 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,[3] although it was eventually sold for £8000.[4] It is reported that the stone originally came from a mine near Arusha, Tanzania.[5]