Diamonds Glossary

Brightness

Sometimes called brilliance, is the level of light that radiates up from within the diamond just as a spot light gets brighter by twisting its dimmer switch. Brightness can best be understood by viewing a diagram of a diamond’s silhouette.

Carat weight

Weight of measure for a diamond. One carat is equal to approximately one-fifth of a gram

Grading Report

Document that is provided with a loose diamond containing the diamonds attributes. GIA is the gold standard for grading reports.

Clarity

The natural birthmarks that are formed within the diamond as nature transforms it from a lump of coal (carbon) into a magnificent crystal.

Color

The absence of body tone. Graded on a scale of D-Z, the "best" color for a diamond is D "Colorless".

Culet

The bottom facet of a diamond. If the bottom of a diamond comes to a complete point then there is no culet. If it has a very small flat surface (almost imperceptible) then it has a culet.

Cut

The level of design and craftsmanship of transforming a diamond from a raw crystal to a polished gem.

Design

Describes the brightness, weight-ratio, fire and scintillation of the diamond for round diamonds. For fancy shaped diamonds, design also includes proper scale of the overall shape.

Durability

The diamond's likelihood of resisting chipping or breaking.

Fancy-shape

Diamond shape other than round.

Fire

Sometimes called dispersion, describes the colors-of-a-rainbow that appear in a diamond.

Fluorescence

The blue "glow-in-the-dark" effect that some diamonds have when exposed to ultraviolet light just like the posters near "black-light" lamps.

GIA

Gemological Institute of America; Established in 1931, GIA is the world's largest and most respected nonprofit institute of gemological research and learning.

Hue

The GIA specifies 31 gemstone hues for fancy colored diamonds. They include terms such as blue, slightly greenish blue, very slightly greenish blue, bluish green, etc.

Polish

Polish describes the quality of a diamond’s surface. Individual surfaces must join invisibly, with seamless edges, so that the diamond appears as a solid mono-lithe. Polish lines must disappear.

Scintillation

Describes the sparkling or twinkling effect given off as diamonds are moving about. It looks as if you are seeing bright white flashes of mini-fireworks within the diamond.

Shape

Pattern of a cut diamond when viewed from the top.

Silhouette

The shape you see when viewing a diamond from the side.

Symmetry

The alignment of the diamond surface (facets).

Weight-ratio

The relationship between the diamond size (viewed from the top) and its weight.

Workmanship

Describes the symmetry, polish, and durability of the diamond.