Glossary of terms

Blemishes
This term is used to when the diamond has scratches or marks on the external area of the stone.
Brilliance
Liveliness or sparkle in a stone when light is reflected from the surface and from the internal refraction of light.
Carat
Refers to the measure of weight of a diamond.
Carbon Spots
Included crystals that have a dark appearance, rather than a white or transparent appearance when viewed under a microscope. In most cases, these dark inclusions are not visible to the naked eye, and do not affect the brilliance of the diamond.
Clarity
A diamond often has natural imperfections, commonly referred to as "nature's fingerprints". Inclusions can be white, black, colourless or even red or green. Most inclusions are undetectable by the human eye and can only be seen with 10x magnification. Inclusions are ranked on a scale of perfection called 'clarity' ranging from IF (Internally Flawless) through to I (Included).

Clouds
A grouping of a number of extremely tiny inclusions that are too small to be distinguishable from one another, even under magnification. The result is that, under a microscope, this grouping often looks like a soft transparent cloud inside the diamond. Of course, clouds cannot be seen with the naked eye. Usually, this sort of inclusion does not significantly impact a diamond's clarity grade.
Colour
Diamonds are graded on a colour scale established some 70 years ago by the GIA (Gemological Institute of America). The scale ranges from D (rare white) to Z (yellow). For more information, please visit our diamond education page.
Culet
The bottom point of the diamond. Occasionally, the culet of the diamond is a surface instead of a point.
Cut
This refers to the angles and proportions a skilled craftsman creates in transforming a rough diamond into a polished diamond. Based on scientific formulae, a well cut diamond will internally reflect light from one mirror-like facet to another and disperse and reflect it through the top of the stone. This results in a display of fire and brilliance.
Depth
The height of a diamond from the culet to the table. The depth is measured in millimeters, or as a percentage of diameter. Diamond
hed and polished diamond.

Proportions
The proportions of a diamond are very important, so that the maximum amount of light can be reflected off and out of a stone. Proportion is the relationship between the angles of the facets of the crown and pavilion.
Symmetry
A diamond's symmetry is the arrangement of the facets and finished angles, created by the diamond cutter. Excellent symmetry of a well cut and well proportioned diamond can have a great effect on the diamond's brilliance and fire.
Table Facet
This is the largest facet of a diamond. It is located on top of the stone.
Table Spread
Term used to describe the width of the table facet often expressed as a percentage of the total width of the stone.