Gemstone Type : Natural Blue Star Sapphire Approx. Weight (ct) : 2.00 Ct. Shape: Oval Cabochan Size/Dimension (LxHxW) : 9 x 7 x 3 MM Color : Blue Star 6 Rays Clarity : Opaque Luster : Fine Origin : Africa Hardness : 9 Specific Gravity : 3.9 - 4.1 Refractive Index : 1.76 - 1.78 Chemical Composition : Al203