The 4C's provide a way to objectively compare and evaluate diamonds, but numbers alone can't describe a diamond's mysterious and captivating beauty - for that, you'll have to visit your local jeweller to see one for yourself.
The cut grade measure how the individual proportions combine to effect the beauty of a diamond. Diamonds with a high cut grade will have a high degree of brightness, fire (rainbow colours) and scintillation (sparkle). High cut grades include "Excellent" and "Very Good" mid range includes "Good", and the low end includes "Fair" and "Poor".
Diamonds can be cut in various shapes. Fancy shapes is the term given to non-round shapes. Rounds are by far the most popular shape. Princess Cut is the most popular fancy shape.
The colour scale extends from D (colourless) to Z (light yellow or brown). Although many people think of gem quality diamonds as colourless, truly colourless diamonds are actually very rare. Colour grades are determined by comparing each diamond to a master set. Each letter grade represents a range of colour and is a measure of how noticeable colour is.
The clarity scale includes eleven clarity grades ranging from Flawless to I3.
Because diamonds form under tremendous heat & pressure, it is extremely rare to find a diamond that lacks any internal and external characteristics. These characteristics are a by-product of its formation and help gemologists separate natural diamonds from synthetics and stimulants, and identify individual stones.
One carat equals 200 milligrams in weight. For diamonds under one carat, each carat is divided into 100 points - similar to pennies in a dollar. 0.75ct. = 75 points, 1/2 ct. = 50 points.