Which term denotes the highest degree of luster possible in a transparent material?

Which term denotes the highest degree of luster possible in a transparent material?

• A. Bast
• B. Adamantine luster
• C. Annealing
• D. Alluvial deposit

Answer: (B)

Luster describes how a mineral’s surface reflects light, and among transparent materials, the highest degree of this reflection is adamantine luster—a diamond-like, brilliant shine that is exceptionally intense and sharp. This term signals an extraordinary level of light interaction, typically seen in materials with very high refractive index and dispersion, like diamond. The other terms don’t relate to how light behaves on a mineral’s surface: one is a plant fiber, another is a heat-treatment process, and the last is a type of sediment. They don’t describe luster, so they aren’t used to denote the brightness or quality of a mineral’s shine.

Luster describes how a mineral’s surface reflects light, and among transparent materials, the highest degree of this reflection is adamantine luster—a diamond-like, brilliant shine that is exceptionally intense and sharp. This term signals an extraordinary level of light interaction, typically seen in materials with very high refractive index and dispersion, like diamond.

The other terms don’t relate to how light behaves on a mineral’s surface: one is a plant fiber, another is a heat-treatment process, and the last is a type of sediment. They don’t describe luster, so they aren’t used to denote the brightness or quality of a mineral’s shine.