Expansion: Topaz is a silicate mineral of Aluminium and Fluorine. Common Topaz in colourless, though trace element impurities can make it pale blue, golden brown to yellow orange. Topaz in the market may be fake or has been treated with heat, or radiation, to make the stone deep blue, reddish-orange, pale green, pink, or purple. Topaz is the hardest silicate and one of the hardest naturally occurring crystals. It has a low refractive index which means it will not shine as brightly as other cut gemstones.
