Common Jewelry Terms

Blemish
Imperfections found on the surface of a Diamond.
Brilliance
describes how well a diamond reflects white light.
Carat
is a unit of weight measurement used for weighing diamonds. One carat equals 0.2 grams or 200 milligrams. 142 carats equals one (1) avoirdupois ounce.
Clarity
measures the degree of visibility of surface blemishes or internal inclusions of a diamond.
Cloud
Minor inclusion appearing milky rather than dark or ash like, only minimally detracting from the stone's appearance.
Color
measures the tint or internal color of a diamond, ranging from colorless to light brown or yellow.
Crown
refers to the upper domed surface above the girdle of a cut diamond. The angle of the crown between the girdle and the table is considered acceptable at between 30.0-37.0 degrees. Crown height is considered acceptable when between 11.0-16.2% of the girdle's diameter.
CT or CTS
Stands for total carat weight of singular stone.
CTW
Indicates the total diamond carat weight of the jewelry item.
Culet
is the end point of the pavilion, finer being considered better, however a sharp point is susceptible to chipping.
Cut
refers the shape (round, square, emerald, pear, oval, marquis, etc.) and proportions of a cut diamond.
Depth
is the vertical height of the diamond from the table to the cutlet. Considered acceptable when between 57.0 to 65.0% of the girdle's diameter.
Eye Clean
Diamond appears to be free of surface blemishes and inclusions to the naked eye. Diamonds graded SI-2 or better will appear to be eye clean.
 Facets
are the small polished plane surfaces of a cut gem stone. A brilliant (round), full-cut diamond has 56 facets, while stones under 3 points can have as few as 16 (single cut).
Finish
Refers to the quality of the diamond's polish and symmetry.
Fire
Describes the intensity and diversity of the light spectrum (rainbow colors) emanating from a diamond.
Fluorescence
Refers to the emission of photoluminescence by a diamond detectable under a black light. Blue fluorescence can enhance a diamonds color, but other colors are considered less desirable.
Girdle
refers to the edge where the crown and pavilion of a cut diamond meet, marking the maximum diameter or width of the diamond. A girdle width of between 2.0-4.0% of the girdle's diameter is considered acceptable. Too sharp or thin a girdle increases the likelihood of chipping.
Girdle Diameter
is the diameter of the diamond at the point where the crown and pavilion meet. Other dimension characteristics of a cut diamond are expressed as a percentage (%) of the girdle diameter.
Included
refers to the internal defects of a diamond, appearing as ash like flakes, cracks, clouds, or other imperfections.
Make
Describes the diamond's cut and proportions.
Pavilion
is the tapered underhalf or base of a cut diamond below the girdle. The angle of the pavilion from the girdle to the cutlet is considered acceptable when between 39.7-41.7 degrees. Pavilion depth is considered acceptable when between 41.5-45.5% of the girdle's diameter.
Point
is a unit of weight equal to 1/100 of a carat, 100 points equaling one carat, and written as 1.00 carat.
Polish
Describes the luster of a diamond's exterior finish.
Symmetry
Describes if the diamond is true to its desired shape and is in balanced proportions.
Table
is the flat top surface of a cut diamond. Table diameter is considered acceptable when between 51.4-66.0% of the girdle's diameter.