Diamond Guide - The Four Cs

The Four Cs are used throughout the world to classify the rarity of diamonds. The four characteristics are Carat, Clarity, Colour and Cut. A diamond’s beauty, rarity, and price depend on the interplay of all the four Cs. No one C is more important than another in terms of beauty and it is important to note that none of the four Cs will diminish in value over time.

Carat
The carat is a measure of a diamond’s mass.

Carat is often confused with size even though it is actually a measure of mass. One carat is exactly 200 milligrams. One carat can also be divided into 100 points. A .75 carat diamond is the same as a 75-points or 3/4 carat diamond.

Since larger diamonds are found less frequently in nature, a 1 carat diamond will cost more than twice a 1/2-carat diamond (assuming colour, clarity and cut remain constant).

Clarity
The presence of inclusions in a diamond.

Inclusions are natural identifying characteristics such as minerals or fractures. These are formed while diamonds are created in the earth. They appear as tiny crystals, clouds or feathers under a jeweller’s magnifying loupe.

Inclusions are ranked on a scale of perfection, known as clarity. The clarity scale, ranging from F (Flawless) to Included (I), is based on the visibility of inclusions at a magnification of 10x. The greater a diamond’s clarity, the more brilliant, valuable and rare it is.

Colour
The degree to which a diamond is colourless.

Diamonds range in colour from icy winter whites to warm summer whites. Diamonds are graded on a colour scale which ranges from D (colourless) to Z.

Warmer coloured diamonds (K-Z) ‘glow’ when set in yellow gold. Icy whites (D-J) look stunning set in white gold or platinum. Colour differences are very subtle and it is very difficult to see the difference between, say, an E and an F. Therefore, colours are graded under controlled lighting conditions and are compared to a master set for accuracy.

Cut
The angles and proportions of a diamond.

Princess Cut Diamond
Princess Cut

Round Cut Diamond
Brilliant cut

Based on scientific formulas, 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 brilliance and fire which is missing in deep or shallow-cut diamonds.

Cut also refers to shape - brilliant, princess, or heart for example. Since a round diamond is symmetrical and capable of reflecting nearly all the light that enters, it is the most brilliant of all diamond shapes and follows specific proportional guidelines.


Conflict Diamond Policy

Every supplier of gem stones to Clogau Gold has given a written assurance that the diamonds have been sourced from conflict-free countries and conform to the terms of the Kimberley Process Certification Scheme which came into effect in January 2003.