Diamond – Natural, Faceted, Colorless

The table is the large, horizontal facet on top of a gem that acts as a window to its interior. Viewing an expertly cut and well-polished facet is essential for getting an accurate reading of a gem's luster with a reflectometer. Faceted diamond, photo by James St. John. Licensed under CC By 2.0.

Article: What is a Gem Reflectometer?

Credit: James St. John