Star Corundum (Lattice-Diffused) Gemstone & Information | Gemopedia by JTV | Gemopedia™

Corundum with star induced by lattice diffusion has been treated with a heat treatment at high temperatures with beryllium that deeply penetrates the gem material to alter the color. This gem exhibits the optical phenomenon called asterism, a star-like pattern created on the surface of a gemstone when light encounters parallel fibrous, or needle-like, inclusions within its crystal structure. Light that strikes the inclusions within the gem reflects off of the inclusions, creating narrow bands of light.