Blue Topaz Facts
Colour: Topaz comes in a variety of colours; with blue topaz being a popular colour.
Hardness: 8 (on Moh’s hardness scale.)
Specific Gravity: 3.54. This is an indication of the stone's density, calculated by comparing the stone's weight with the weight of an equal volume of water.
Refractive Index: 1.62 to 1.63. This is a measure of the amount light is bent from its original path when passing through a stone.
Chemical composition: Aluminium fluorohydeoxysilicate. Part of the Topaz family of minerals.
Principal sources: Brazil, USA, Sri Lanka, the former USSR and Australia.