Truly flawless diamonds are very rare, and very expensive, so you will seldom face the task of selecting a perfect diamond. It is a fairly simple matter to find beautiful diamonds with no flaws visible to the naked eye and buy them at reasonable prices.
Diamonds are graded using a system that judges the stone on its colour, clarity, cut and carat weight - commonly known as the "Four C's."
In this section, you will learn what each of the C's means and how it affects the value of the diamond.
'C' for cut
The cut of a diamond refers not only to the shape of the diamond and number of facets, but also to the quality of the cut. A diamond with uneven or poorly proportioned facets won't be given the same grade of cut as an ideally proportioned and masterfully cut stone. This information will be found on the certificate of a certified diamond.
How a diamond has been cut, polished and to what proportion and symmetry are of utmost importance since these factors determine the life, brilliances and dispersion of the diamond. If these factors fall below standard, the appearance of the diamond will be adversely affected.
Although most diamonds on the market today are round brilliants, there are many different shapes available. The following chart shows some of the most popular shapes:
'C' for clarity
It is very common for diamonds to be formed with slight imperfections. These are known as "inclusions" and can come in many forms, including tiny white points, dark dots, or feathery cracks. The fewer inclusions, the more the stone is worth. A diamond's clarity ranking is determined by the number, size, type and placement of the inclusions.
In order to grade the clarity of a diamond, it is necessary to observe the number and nature of any internal characteristics in the stone as well as their size and position. This Diamond Clarity Grading is carried out using the IGI scope and a loupe 10x under the experienced eye of laboratory gemologists. A diamond is said to be “Internally Flawless” when it presents no internal defects under 10x magnifications.
'C' for color
Most diamonds appear colorless but actually have slight tones of yellow or brown. The closer the stone comes to colorless, the more valuable it is. Diamonds are graded on a color scale ranging from D (colorless) to Z (heavily tinted.)
'C' for carat
The weight or size of a diamond is measured in carats (ct.). A carat is 0.2 grams and there are 100 points (or 200 milligrams) per carat. The Carat measurement of a diamond is actually a measurement of the Diamond's weight rather than its size or diameter. Do not confuse carat with karat. Carat refers to stone weight while karat refers to fineness of gold.