TOPAZ


Meaning of TOPAZ in English

Aluminum silicate mineral , Al 2 SiO 4 (F,OH) 2 , that is valued as a gemstone.

It is formed by fluorine-bearing vapours given off during the last stages of the crystallization of igneous rock s. Pure topaz may be colourless and, when brilliant-cut, has been mistaken for diamond. It may also be various shades of yellow, blue, or brown. Imperial topaz, with vivid reddish orange colour, from Minas Gerais, Braz., is very highly valued.

Topaz from Minas Gerais state, Brazil

Lee Boltin

Britannica English dictionary.      Английский словарь Британика.