What does the term “brilliance” refer to in diamond terminology?

The term “brilliance” in diamond terminology specifically refers to the return of white light from the diamond. When light enters the diamond, it interacts with the facets and is reflected back to the viewer's eye, creating a visual effect known as brilliance. This effect encompasses how effectively the diamond can reflect white light, which is a crucial element in determining the overall beauty and appeal of the gemstone.

The other terms in the options address different aspects of diamond characteristics. For instance, the sparkle of colors relates to "fire," which is the dispersion of light into various colors as it exits the diamond. Cut quality pertains to the overall proportion, symmetry, and finish of the diamond, which indeed influences both brilliance and fire but is not synonymous with brilliance itself. Internal clarity refers to the presence or absence of inclusions and blemishes within the diamond, affecting its overall clarity grade, but it does not directly define brilliance.