Adamantine: A hard, brilliant luster. Another common nonmetallic luster is called translucent luster, where you can see into the mineral, but not completely through it. A mineral that displays a transparent luster transmits light completely through it, resembling glass.
Judging Pearls Luster Luster is a major factor in determining a pearl's value. The more lustrous a pearl is, the more high quality. it's perceived to be—and thus the more expensive it is. A truly lustrous pearl will have a jewel-like glow, with rainbow overtones. When a pearl appears too perfectly white or too dull and chalky, it is of low quality.