Gemstone Type : Natural Color Change Alexandrite Cats Eye Approx. Weight (ct) : 0.50 Cts. Shape : Oval Cabochan Size/Dimension : 4 x 4.5 MM Depth : 2.5 MM Color : Green With Purple Clarity : Translucent Luster : Good Origin : Srilanka Hardness : 8.5 Specific Gravity : 3.2+ Refractive Index : 1.742 - 1.749 Chemical Composition : BeAl203 Treatment : Natural