Item No : 6874321 Gemstone Type : Natural Tanzanite Approx. Weight (ct) : 0.25 Ct. Shape : Oval Size/Dimension : 5.8 x 3.9 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)