Sapphire
The name “sapphire” can also apply to any corundum that’s not ruby, another corundum variety. Depending on their trace element content, sapphire varieties of the mineral corundum might be blue, yellow, green, orange, pink, purple or even show a six-rayed star if cut as a cabochon.
Birthstones & Anniversaries
Sapphire is the birthstone for September and the gem of the 5th and 45th anniversaries.
Facts
Mineral: Corundum
Chemistry: Al2O3
Colour: Every colour but red
Refractive index: 1.762 to 1.770
Birefringence: 0.008 to 0.010
Specific gravity: 4.00
Mohs Hardness: 9
