Bezel
A type of diamond setting: The thing that makes the bezel special is its simplicity and strength and its suitability for every shape of diamond. Another advantage to this setting is that often, diamonds look bigger and brighter than they actually are.

Carat
Carat is the terminology used to define the weight of a diamond and should not be confused with Karat (The definition of the purity of gold). The term originates from use of the seed of the carob tree as a precise weight as all the seeds were thought to be to be of uniform weight and was used in the past to measure the weight of diamonds. Today, one carat is equal to 200 Mg.

Certificate
In the diamond industry, a certificate is the ID of a specific diamond and contains the diamond weight, exact measurements, cut and quality. The certificate can be used to accurately identify a specific stone. If you are looking to purchase loose diamonds, the certificate provides you with vital information that enables you to make an informed decision.

Channel
Another style of diamond setting. This is a very strong, long lasting setting with the added advantage that the diamonds sit flush to the setting thus minimizing the risk of the diamonds getting caught on clothes and also, when a number of stones are set together, provides a brilliant line of light.

Clarity
All diamonds have some impurities or blemishes. The type and quantity of impurities, defines the clarity of the stone. These impurities are unique to every diamond and act as a form of fingerprint so that no two diamonds are every exactly alike. The clarity of a
diamond is defined by five parameters:

Number
the number of impurities or blemishes in the stone.

Size
The size of the impurities.

Relief
Whether the impurity easily visible, because of color variations.

Position
The position of the impurities within the stone.

Nature
Are the impurities liable to cause damage to the diamond at some stage?

Color
The less coloration a diamond has, the more valuable it is. Diamonds graded D-F are considered colorless, are the rarest and so the most valuable. Diamonds graded G-J are classed as nearly colorless and the coloration, after mounting, will be almost undetectable to the untrained eye.

Crown angle
This the term used to describe the angle at which a diamond's bezel facets meet the girdle plane or the widest part of the diamond. This angle is usually around 35 degrees but can vary.

Crown height
The crown is the upper part of a cut diamond. The crown height refers to the distance between the crown and the widest part of the diamond.

Culet
A tiny facet at the bottom of a gemstone: Many diamonds have no culet and all the facets meet at one place and form a sharp point that is susceptible to damage. A culet can help reduce the risks of damage to the stone.

Cut
The cut of a diamond refers to its proportions of the diamond and the way it was cut or shaped. A well cut diamond is brighter and more alive than a poorly cut stone which will seem lifeless. The ideal cut diamond is the absolute measure of perfection

Depth
Depth is the term used to define the distance from the top of a diamond to the bottom. As with the cut, the proportions of the diamond, including its depth are vital to the quality of the finished stone.

Fluorescence
Some diamonds exhibit a blue glow when placed under an ultra violet light. There are varying levels of florescence, but none that can be seen in normal light so this should in no way affect the quality of your stone..

Girdle
The narrow rim around the diamond separating the crown (top) and pavilion (bottom) of the diamond. The girdle has the largest diameter of any part of the stone.

Measurements
The dimensions of a stone including height, diameter and size.  Measurements are usually expressed in millimeters.

Pave
In a pavé setting, diamonds are set into small holes almost level with the surface of the ring.  This setting gives an appearance of a river of sparkling light.

Pavilion angle
This is the angle formed where pavilion’s (bottom section of the diamond) main facets and the plane of the girdle (the diamonds thickest part) meet..

Pavilion depth
This is the distance from the girdle plane to the culet and usually expressed as a percentage of the girdle diameter

Plot
A color diagram describing all the major clarity characteristics of a specific diamond. This diagram will appear on any certificate issued for the stone.

Polish
After a diamond is cut to the desired shape it goes through a process of polishing to give it a mirror like finish and enhance the light reflected from or through the stone.

Prong
This is the most popular style or setting for engagement rings. Prong settings are made up of 4 or 6 metal prongs that are formed around the stone and bent over the top to hold it in place.

Shape
The standard diamond shapes. There are nine common diamond shapes: round (the most popular shape of the nine), princess, radiant, oval, pear, emerald, trillion, marquise and heart.

Symmetry
This is the grading system that describes the uniformity of a stone's cut. Grades range from poor (the lowest), fair, good, very good and excellent. A diamond that is cut with poor symmetry will adversely affect a diamond's brilliance through loss of light

Table
The flat surface area located directly at the top of the diamond. The table is also the largest facet of the diamond and the most important. It is, or should be, a symmetrical octagon.