Property of Blue Sapphire
Chemical composition : Al2O3, Aluminium oxide
Crystal system : Trigonal
Refractive index (RI) : 1.76-1.77
Specific gravity (SG) : 3.80-4.05
Birefringence : 0.008-0.012
Optical nature : (DR) uniaxial
Luster : Vitreous
Hardness : 9
Colour : Blue (Its blue color originated from Iron and Titanium.)
Localities : Thailand, Burma, Cambodia, Vietnam, Madagascar, Australia, Tanzania, India, China and America.
Blue sapphires are most often found with inclusions inside. Sapphires with less inclusion has more price. The clarity of the sapphire plays important role on the price of blue sapphire. Importantly, purchasers should be aware of confusion between real blue sapphire and other blue gems such as tanzanite, blue zircon, blue spinel,blue kyanite and aquamarine etc. Also be careful of synthetic blue sapphire which can be observed the inclusions in the gemstone from the professional gem dealers. It requires the expertise to differentiate between natural and synthetic blue sapphire. Therefore, it is important that purchasers should buy blue sapphire from the trusted sources.
Picture : Faceted cut and Cabochon blue sapphire.
Blue sapphire quality improvement is normally processed by heat treatment in order to make its color more attactive which is worldwide acceptable in the market.
Picture : Rough Blue Sapphire