4 Cs of Diamonds
Various characteristics of diamonds are graded and categorized by the diamond industry. Learning about diamonds is first learning about the "four Cs" of diamonds which are considered the most important part of understanding a diamond:
- Cut
- Clarity
- Color
- Carat weight
These are the criteria jewelers use when grading diamonds and they're the ones you'll need to understand to buy the right diamond for you.
And then there's the "Fifth C":
Cut is probably the most important, and most challenging, of the four Cs to understand. The brilliance of a diamond depends heavily on its cut. GIA & EGL have recently been grading the cut of the diamond to make take the guess work out for the consumer. This makes it easier for buyers to get the best C’s combination for the carat weight and their budget.
Most diamonds contain some inner flaws, or inclusions, that occur during the formation process. The visibility, number and size of these inclusions determine what is called the clarity of a diamond. Diamonds that have higher clarity will create more brilliance, and thus are more highly prized, and priced. The brilliance of a diamond is lost when the clarity of the diamond is with in I1-I3 range.
The following table explains the diamond clarity (inside the diamond):
|
IF |
VVS1 |
VVS2 |
VS1 |
VS2 |
SI1 |
SI2 |
SI3 |
I1 |
I2 |
I3 |
|
FLAWLESS |
EXTREMELY DIFFICULT TO SEE INCLUSIONS UNDER 10x MAGNIFICATION |
DIFFICULT TO SEE INCLUSIONS UNDER 10x MAGNIFICATION |
INCLUSIONS VISIBLE UNDER 10X MAGNIFICATION |
INCLUSIONS VISIBLE TO NAKED EYE |
Colorless and Near Colorless diamonds are the most desirable since they allow the most refraction of light (sparkle). Off white diamonds absorb light, inhibiting brilliance and sparkle.
While many diamonds appear colorless, or white, they may actually have subtle yellow or brown tones that can be detected when comparing diamonds side by side. Diamonds were formed under intense heat and pressure, and traces of other elements may have been incorporated into their atomic structure accounting for the variances in color.
Diamond color grades start at D and continue down through the alphabet. Colorless diamonds, graded D, are extremely rare and very valuable. The closer a diamond is to being colorless, the more valuable and rare it is.
The color of a diamond is graded with the diamond upside down before it is set in a mounting. The first three colors D, E, F are often called collection color. The subtle changes in collection color are so minute that it is difficult to identify them in the smaller sizes. Although the presence of color makes a diamond less rare and valuable, some diamonds come out of the ground in vivid "fancy" colors - well defined reds, blues, pinks, greens, and bright yellows. These are highly priced and extremely rare.
A carat is the universal measure of weight for a diamond. This is the easiest of the 4 C’s to determine. But keep in mind that two diamonds of equal size can have a different value because of the other C’s in diamond. Because large diamonds are found less commonly than small diamonds, the price of a diamond rises exponentionaly to its size
The diamond certificate, which is sometimes called a grading report, is a complete evaluation of your diamond that has been performed by a qualified professional with the help of special gemological instruments. Each stone bears its own recognizable, individual characteristics, which is listed on the certificate. The certificate of a diamond does not have the value of the diamond. The value for the diamond comes from the jeweler.
It is a good idea to buy a diamond with an independent grading report (or cert), like those shown.
Grading reports do not give a value; appraisals do that. They give an independent expert opinion on quality for loose or unset gems. Most grading institutes have labs or services worldwide and do not sell diamonds.
There can be slight differences in the grades and prices of the same diamonds graded and priced by different labs.
More GIA diamonds are listed on the internet. IGI and EGL certified diamonds are common in stores; these labs bundle appraisal and grading services together. Appraisals go out of date, but unless the diamond is damaged, the cert should be good forever. Store it in a safe place.
Internet Diamond Listings July 2004
GIA........72.9%
EGL........22.8%
AGS........2.5%
IGI........1.4%
HRD........0.4%
If you plan to buy a diamond on the internet, ask the vendor to firstly send your stone to an independent appraiser to ensure it matches its Grading Report and possibly make an insurance appraisal. Stones can be switched, deceitfully or accidentally and honest vendors will happily do this. The appraiser will then ship the stone to you, or back to the vendor to set the stone into a mount. |
) 
