Brilliance: The amount of white light reflected that radiates from the diamond's surface. The properly proportioned cut equals a more brilliant diamond.

Brilliant Cut: A round diamond that measures 58 facets.

Carat: Measurement used for scaling the weight of a diamond. One carat is equal to one fifth of a gram.

Clarity: A graded scale that measures the amount of imperfections within a diamond. The ranges from flawless (FL) to severely included (I3).

Cloud: A minor inclusion within a diamond.

Color: Color tones of a diamond that are graded on a scale of D (colorless) to Z (yellow brown). 

Culet: The bottom point of the diamond which may or may not contain a facet. 

Cut: The proportion of angle and geometric shape that encompasses both shape and percentage of stone. Determines the stone's sparkle and radiance capabilities.

Ideal Cut: A round diamond that is perfectly proportioned. See Hearts and Arrows.

Very Good Cut (Premium): A proportioned cut that maximizes brilliance, reflection and fire. Meets the highest standards and dimensions for a quality diamond.

Good Cut: An acceptable and more reasonably priced cut with decent proportions.

Fair Cut: While still capturing some sparkle, this cut is made to maximize the diamond's carat weight.

Poor Cut: A clearly dull and lifeless diamond that sacrifices proportion and quality.

Depth: A diamond's height from culet to table.

Depth %: Height divided by width. Determines brilliance and sparkle.

Eye-clean: When viewing with the naked eye, a diamond with no visible inclusions or imperfections.

Facet: A diamond's flat, polished surfaces.

Fire: Reflected color light that radiates from the inside, out.

Fluorescence: When exposed to ultraviolet light, an illuminating bluish color that glows from the diamond surface, which usually doesn't affect appearance or quality.

Girdle: A diamond's narrow band that encircles the width.

Inclusion: An imperfection within a diamond that typically manifests in the crystal. May or may not be visible to the naked eye but noticeble when magnified.

Make: The diamond's cut proportions. The better the make, the better the diamond.

Pavilion: A diamond's bottom portion.

Point: One hundredth of a carat.

Polish: The external finish of a stone, which ranges from excellent to poor.

Sparkle: The amount of reflected light that radiates from a diamond's surface and combines both fire and brilliance.

Symmetry: The overall unity and proportion of a stone's cut.  Symmetry ranges from poor to excellent.

Table:  The top of the diamond that carries the largest facet of the diamond.

Table %: The total diameter of the diamond that divides the width of the table and is critical in determining the sparkle of the stone.