Diamond Glossary

Diamond Related Terms

BLEMISH: A flaw on the exterior surface of a diamond, such as a scratch, abrasion, nick or chip.

BLUE-WHITE: Refers to a diamond that glows (fluoresces) blue under ultraviolet (UV) light.

BRILLIANCE: The intensity of white light reflected up through the top of a diamond.

BRILLIANT: A 58-facet round diamond (sometimes called the American Brilliant).

CARAT: A unit of weight, equal to 200 milligrams, or one-fifth of a gram.

CARBON: The raw material of a diamonds.

CLARITY: A grade given to a diamond to describe the level of “impurities” or inclusions.

CLOUD: A cluster of very small inclusions, or internal flaws, inside a diamond that give a cloud effect.

COLOR: A grade given to a diamond to describe the tones of color in particular stone.

CROWN: The top of a diamond from the girdle to the table.

CULET: The bottom facet at the tip of a diamond, usually very small.

CUT: Commonly used to refer to the geometric proportions that a diamond is cut.

DIAMETER: The width of a diamond, measured around the girdle.

DEPTH: The height of a diamond from the culet to the table.

DISPERSION: The result of white light splitting into all the colors of the rainbow within a diamond, also called fire.

EYE-CLEAN: A term referring to a diamond that has no inclusions or blemishes visible to the naked eye when viewed from 12 inches away.

FACET: A polished flat surface on a diamond.

FACE UP: View of a diamond from the top of the stone.

FIRE: The result of white light splitting into all the colors of the rainbow within a diamond, also called dispersion.

FLAW: Any external or internal imperfection in a diamond.

FLUORESCENCE: A diamond’s reaction to ultraviolet (UV) light, causing the stone to glow in various colors.

FULL-CUT: A diamond with 58 or more facets.

GEMOLOGIST: A person who has been trained and accredited in diamonds and colored stones.

GIA: Gemological Institute of America is an independent, non-profit educational organization which sets and upholds standards for grading diamonds and other precious stones.

GIRDLE: The narrow, unpolished band around the widest part of a diamond; the girdle separates the crown and the pavilion of the stone.

HEAD: The prongs which hold a diamond in its setting.

INCLUSION: A natural flaw or impurity within a diamond, such as carbon spots or fractures.

KARAT: The measure of the purity of gold.

LASER-DRILLED: A diamond that has been treated with a laser to remove carbon spots.

LOUPE: A small magnifying glass.

MAKE: The quality of the finish and proportions of a finished diamond.

OFF-MAKE: A poorly proportioned diamond.

PAVILION: The bottom part of a diamond, from below the girdle to the culet at the bottom tip.

POINT: A measure of diamond weight. One point equals 1/100th of a carat.

POLISH: A grade given to the external finish of a stone, from poor to excellent.

PROPORTIONS: The cutting quality relative to the depth percentage, table percentage, girdle percentage, symmetry and crown and pavilion angle.

SEMI-MOUNT: A setting which is complete except for the main stone.

SINGLE-CUT: A diamond with only 16 or 17 facets.

SPARKLE: The amount of light reflecting from a diamond. The combination of fire (dispersion) and brilliance. Sometimes called “scintillation”

SCINTILLATION: Flashes of reflected light from a diamond when it is moved. Commonly referred to as sparkle.

SYMMETRY: The overall uniformity of a diamond’s cut, graded from poor to Ideal.

TIFFANY: A simple, elegant 2-3mm ring setting with a head that holds a single diamond.

TABLE: The large flat facet on the top of a diamond.