Luster describes

Luster describes

• A. The appearance of a material's surface in reflected light.
• B. The color grading of a diamond
• C. The density of the diamond
• D. The hardness measured on Mohs scale

Answer: (A)

Luster is about how a gem’s surface appears when light reflects off it. For diamonds, this means how shiny and reflective the surface looks after light hits the facets. A well-polished diamond often shows a bright, glassy or adamantine luster because light reflects cleanly from the smooth, faceted surface. This property is about surface shine in reflected light, not about color, how heavy the stone is, or how hard it is to scratch. Color grading relates to hue and tone, density is a measure of mass per volume, and hardness is about scratch resistance. So describing luster as the appearance of a material’s surface in reflected light best captures what is being observed.

Luster is about how a gem’s surface appears when light reflects off it. For diamonds, this means how shiny and reflective the surface looks after light hits the facets. A well-polished diamond often shows a bright, glassy or adamantine luster because light reflects cleanly from the smooth, faceted surface. This property is about surface shine in reflected light, not about color, how heavy the stone is, or how hard it is to scratch. Color grading relates to hue and tone, density is a measure of mass per volume, and hardness is about scratch resistance. So describing luster as the appearance of a material’s surface in reflected light best captures what is being observed.