Blue John Luster
Optical Properties of Blue John are its behavioral responses towards light. While few optical properties can be identified with naked eyes, other require special instruments by the gemologists to identify them. Blue John optical properties like luster, clarity, refractive index etc. are used to determine the non-destructive methods during gemstone identification and evaluation.
Blue John luster is the quantity of light the crystal reflects when light is incident on it. Blue John which is commonly found in White, Colorless, Blue, Red, Green, Yellow, Violet color, is Transparent in nature.