Item No : 5753082 Gemstone Type : Natural Tanzanite Approx. Weight (ct) : 0.25 Ct. Shape : Oval Cut Size/Dimension : 4 x 3 MM Color : Lavender Blue Clarity : Transparent Luster : Good Origin : Tanzania Hardness : 6.5 - 7 Specific Gravity : 1.68 - 1.72 Refractive Index : 1.68 - 1.72 Chemical Composition : Ca2Al3(Si04)3(OH), Treatment : Unheated Quantity : 1 Pc (s)