Chemical Composition: Aluminium Oxide, Al 2 O 3
Refractive Index: 1.76 – 1.78
Specific Gravity: 3.80 – 4.05
Crystal System: Trigonal
Moh's Hardness: 9

Ruby’s are apart of the Corundum family and come in varying shades of bright red, pink red, brown red or purple red. They owe their red colour to chromium with some traces of iron, which results in the brown hues.

Browns and purples in Ruby’s are not preferred and are usually heat treated to remove these colours, which result in a red or pink red colour.

Common localities include Burma, Thailand, Sri Lanka, Pakistan, Vietnam