Optical Properties of Howlite 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. Howlite optical properties like luster, clarity, refractive index etc. are used to determine the non-destructive methods during gemstone identification and evaluation.
Howlite luster is the quantity of light the crystal reflects when light is incident on it. Howlite which is commonly found in Blue, Colorless, White color, is Gemmological Tables (2004) More from other references in nature. It possess Vitreous luster.