The Four Cs
Although the diamond industry is a science in itself, in order to give consumers a clear understanding about diamonds, it is useful to have an understanding of the so-called "4Cs" of diamonds. The 4Cs stand for: Color, Clarity, Cut, and Carat (or weight of the diamond). And there is another "C" that has become increasingly important in the past decade or so: Certificates.
Most buyers prefer a larger diamond than a smaller one. The carat weight greatly influences the cost of the diamond since the cost rises significantly per carat. But a 1.00 carat diamond won't cost exactly half the price of a 2.00 carat stone.
When looking to buy a diamond, buyers should try to find one that is as close to the next carat weight as possible. The cost of a 1.94-carat stone will be much less than one weighing 2.00 carats even though there is only a difference of six points between them.
The term carat derives from the fact that the seeds of the Carob were used on precision scales as units of weight for small quantities of precious stones.
The single most important factor in grading and valuing colored diamonds is their color. The color, hue and tone of the diamond is compared to the lightness or darkness of the color to determine the grading, or quality of the stone. The body color of a stone influences the appearance of a diamond and its price. Color is part of the natural composition of the diamond and never changes over time. It is caused by varying quantities of nitrogen and other trace elements present in all diamonds, displacing the carbon atoms within the crystal's structure.
How is the color of a diamond decided? Fortunately, there is an almost universally agreed way of grading – by using the Gemological Institute of America's color scale.
The way a diamond is cut is also critical because it determines the brilliance of the diamond.
This diagram illustrates how vital a perfect cut is because it allows light to enter the stone through the table (the top flat part of the diamond) and go on to the pavilion (the lower angled part) where it is completely reflected back through the table. A poor cut means that light is not reflected entirely – and for the buyer that means the stone does not have as much fire, brilliance and sparkle.
The clarity of a diamond means whether it has inclusions, or flaws, inside it. Most diamonds have flaws – they were formed when the stones were created deep underground millions of years ago. Does the diamond have inclusions? If so, it will command a lower price because its so-called clarity is reduced. Scratches, or blemishes on the exterior of a diamond also has an effect on the clarity. See the diagram below for a quick view of the nature of inclusions.
The diamond industry generally accepts that there are five levels of clarity.
This grade means there are no blemishes on the surface or inclusions in the stone when examined by a skilled grader under 10X magnification.
IF stands for Internally Flawless. The diamond does not have any flaws inside it, but may have some surface blemishes. Such diamonds are extremely rare and, consequently, are the most expensive.
VVS is Very Very Slightly Included of which there are two grades. The diamond has tiny inclusions which are very difficult to detect without a 10x magnification by a trained gemologist.
VS1-VS2 are two grades of Very Slightly Included. These inclusions are so small that they can only be seen with difficulty using 10x magnification.
This means Slightly Included. The inclusions can be more easily seen using 10x magnification.
I1-3 are inclusions which are big enough to be seen using 10x magnification and in some cases the inclusions can be spotted with the naked eye depending on the size of the inclusion.