Diamond Glossary -Every Diamond Terminology Explained

Diamond Glossary -Every Diamond Terminology Explained


Once cut and polished, all diamonds possess a shared set of characteristics, often referred to as the anatomy of the diamond. While the individual proportions, angles and placement of these common characteristics vary for diamonds of different shapes, their definition is the same.


An appraisal documents the key characteristics of an item, such as the carat weight, shape, cut, color, clarity, and measurements of a diamond, and the weight, purity, and styling of a ring (if the diamond is set). An appraisal can often be obtained from the retailer or from an independent appraiser.

Asscher Cut

The modern asscher cut diamond is similar to a square emerald cut, usually with larger step facets, a higher crown, and a smaller table. This combination often produces more brilliance than the emerald cut.


A flaw present on the surface of the diamond, as opposed to an inclusion, which is internal. The degree to which blemishes and inclusions are present in a diamond is indicated by the clarity grade.

Bow Tie

Elongated fancy shapes, such as marquise, oval, pear, and radiant cut diamonds often display an effect commonly known as a "bow-tie". A bow-tie is a dark area that runs right to left across the center of the diamond in the approximate shape of a man's bow tie.


Brilliance refers to the brightness of a diamond, created by the combination of all the white light reflections from the surface and the inside of a polished diamond to the eye.

Brilliant cut

Generally used to refer to diamonds of any shape with facets that are mostly triangular or kite shaped, and that radiate from the center.


A chip on the diamond surface that may include root-like feathers radiating into the diamond.

Carat Weight

a carat is equal to exactly 0.2 grams (about the weight of a paper clip). Carat weight is unrelated to the similar sounding karat, which refers to gold's purity.


An opening or depression in the surface of the diamond, usually the result of a natural flaw in the rough stone.


The process by which a diamond is sent to a third party laboratory for a comprehensive evaluation. Each certificate issued is uniquely numbered, and corresponds to one individual diamond.


A shallow nick in the surface of the diamond, often created during cutting.


Because they are formed deep within the earth, under extreme heat and pressure; virtually all diamonds contain "birthmarks"; small imperfections inside the diamond (called inclusions), or on its surface (called blemishes). Clarity refers to the degree to which these imperfections are present.


A tight grouping of pinpoint inclusions. The individual pinpoints are often impossible to see under 10x magnification, but the cloud they form can be.


In a white diamond, the presence of a yellow tint will lower the price of a diamond. The less body color in a white diamond, the more true color it will reflect, and thus the greater its value.


The entire portion of the diamond that sits above the girdle. The crown includes the table, as well as other crown facets

Crown Angle

Refers to the number of degrees between the plane of the table and the bezel facets


A mineral deposit found inside the diamond, either alone or in groups. The crystal may be colored or colorless, but usually appears black in overhead lighting.


Diamond Culet Size

The culet is the small area at the bottom of a diamond's pavilion. The culet can be a point or a very small facet sitting parallel to the table.


Cut refers not to a diamond's shape (e.g. round, oval, pear, etc.) but to a diamond's proportions, symmetry and polish.


Depth refers to the distance between the culet and the table when the diamond is viewed from the side.

Diamond Treatments

A variety of techniques exist to artificially improve the natural clarity of a diamond – also known as enhancements.

Emerald Cut

The unique look of the emerald cut diamond is created by the step cuts of its pavilion and its large, open table. Instead of the sparkle of a brilliant-cut, emerald cut diamonds produce a hall-of-mirrors effect, with the interplay of light and dark planes.

Extra Facet

Any facet that is not a part of the shape's standard cut. Usually created by the cutter due to a limitation or flaw in the original rough stone.


A facet is a flat polished surface on any side of a diamond. A brilliant cut diamond will have 58 facets (including the culet). A facet is created during the cutting of a rough diamond, and is polished to a glassy smoothness.


A fracture that often has fine lines radiating from it, resembling a feather. Feathers usually appear white or transparent, depending on the viewing angle.


The light that reflects out of a diamond can appear in brilliant white flashes, or in a rainbow of color, referred to as fire


Fluorescence refers to a diamond's tendency to emit a soft colored glow when subjected to ultraviolet light (such as a "black light").


The girdle is the outer edge of the diamond, where the crown (top) meets the pavilion (bottom).


An internal flaw in the diamond. The position, size, number, color, and reflectivity of a diamond's inclusions has a significant impact on its appearance and value. Clarity refers to the degree to which these natural flaws are present. Diamonds graded by the GIA and other labs have their clarity rated on a scale of F (flawless) to i3 (significant inclusions).

Indented Natural

A natural that leaves an actual depression or indentation in the finished diamond's surface.

Laser Inscription

Text which is etched into the girdle of a diamond, usually for purposes of identification.

Length to Width Ratio

The length to width (L/W) ratio is calculated by dividing a diamond's length (the longer measure) by its width (the shorter measure that runs perpendicular to length).

Marquise cut

The marquise cut diamond is a football-shaped, modified brilliant-cut.

Mohs Scale

The Mohs Scale designates the comparative hardness of various natural minerals. The scale runs from 1 (very soft) to 10 (very hard). A diamond, the hardest substance known to man, is the only mineral that is rated 10. This means that it is extremely resistant to scratches or abrasions. Rubies and sapphires are rated 9, and other semi precious gems are rated from 7-8.


Small remains of the original rough stone's surface, left unpolished on the surface of the finished diamond. Usually found on the girdle.


The entire portion of the diamond that sits below the girdle. The pavilion usually constitutes the bulk of a diamond's carat weight and consists of the pavilion facets and culet. Pavilion height may be expressed in millimeters, or as a percentage of a diamond's diameter.


A very small crystal, often whitish in color. When clustered together, these pinpoints can form a cloud.


Polish refers to the degree of smoothness of each facet of a diamond as measured by a gemologist.


Scintillation refers to the intense sparkle of a diamond as it moves. These flashes of black and white are most pronounced in flood lit areas where strong light enters the diamond from multiple angles.


Symmetry refers to how precisely the various facets of a diamond align and intersect. This can include extra or misshapen facets, off center culets and tables, and wavy girdles


Yield refers to the weight of finished diamonds that are cut from the rough stone. Cutting a 1 carat diamond from a 2 carat rough stone would be a higher yield than cutting a 2 carat diamond from a 6 carat rough stone.



Write a comment

Comments are moderated