About Rubies & Sapphires

The name corundum originates from the Sanskrit word kurivinda. It is used to describe the group of gemstones to which both ruby and sapphire belong. The chemical composition of corundum is aluminium oxide (Al2O3) & traces of various transition elements. Rubies contain chromium as their dominant transition element and sapphires contain ferric iron. Corundum crystallizes in a hexagonal (trigonal) form with the six crystal faces meeting at 120 degrees. Gem quality corundum comes in all colours with red corundum described as ruby and all other colours described as a sapphire with the name of the colour as a prefix. Below are some of the physical properties of corundum.