Optical Properties of Sard 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. Sard optical properties like luster, clarity, refractive index etc. are used to determine the non-destructive methods during gemstone identification and evaluation.
Sard luster is the quantity of light the crystal reflects when light is incident on it. Sard which is commonly found in White, Colorless, Blue, Red, Green, Yellow, Violet color, is Translucent in nature. It possess Waxy luster.