Sapphire Facts

Colour: Found in a multitude of fancy colours, though associated with blue when not specified.

Hardness: 9 (on Moh’s hardness scale). Second only to diamond.

Specific Gravity: 3.99/4. 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: 1.76 to 1.77. This is a measure of the amount light is bent from its original path when passing through a stone.

Chemical composition: Aluminium oxide, Al₂O₃. Part of the corundum family of minerals.

Principal sources: Mynmar (Burma), Sri Lanka, India, Thailand, Australia and Nigeria.