Topaz is a silicate mineral of aluminium and fluorine. Topaz crystallizes in the orthorhombic system. Its crystals are mostly prismatic terminated by pyramidal and other faces.

Pure topaz is colorless and transparent but is usually tinted by impurities. Topaz can be wine colored, yellow, pale gray, reddish-orange, or blue brown. It can also be made white, pale green, blue, gold, pink , reddish-yellow or opaque to transparent / translucent.

Orange topaz or precious topaz, is the traditional birthstone of November. It is the symbol of friendship and the state gemstone of Utah of USA.

Mystic topaz is colorless topaz which has been artificially coated giving it the desired rainbow effect.