When purchasing certified diamonds it is important to understand the diamond grading criteria used by the laboratories performing the certification. Diamond grading covers numerous aspects of each individual diamond's qualities, but there are four grades which are critical to understand: Cut, Clarity, Color, and Carat weight.
The Four C's of a diamond:
|Cut:||Cut is probably the most important quality factor, and most challenging, of the four Cs to understand. The brilliance of a diamond depends on its cut.|
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 are clear create more brilliance, and thus are more highly prized, and priced.
Colorless diamonds are the most desirable since they allow the most refraction of light (sparkle). Diamonds with tint color absorb light, inhibiting brilliance.
A carat is the unit of weight by which a diamond is measured. Because large
diamonds are found less commonly than small diamonds, the price of a diamond rises accordingly to its size.
The extra C: Certificates!!
The diamond certificate, which is sometimes called a grading report, is a complete evaluation of a 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.
A carat is a unit of measurement, it's the unit used to weigh a diamond. One carat is equal to 200 milligrams, or 0.2 grams. Size does matter. It is not, however, a measure of your love. Keep in mind that differences in size are clearly visible, even to the untrained eye. So uniform in shape and weight are these little seeds that even today's sophisticated instruments cannot detect more than three one-thousandths of a difference between them.
The process that forms a diamond happens only in very rare circumstances, and typically the natural materials required are found only in small amounts, which means that larger diamonds are uncovered less often than smaller ones. Therefore, large diamonds are rare and have a greater value per carat. For that reason, the price of a diamond rise according to its size.
When jewelers speak of a diamond's color, they are usually referring to the presence or absence of color in white diamonds. Color is a result of the composition of the diamond, and it never changes over time. Because a colorless diamond, like a clear window,
allows more light to pass through it than a colored diamond, colorless diamonds emit more sparkle and fire. The formation process of a diamond ensures that only a few, rare diamonds are truly colorless. Thus the whiter a diamond's color, the greater its value. Diamonds graded G through I show virtually no color that is visible to the untrained eye.
Fancy color diamonds do not follow this rule. These diamonds, which are very rare and very expensive, can be any color from blue to green to bright yellow. They are actually more valuable for their color. To grade 'whiteness' or colorlessness, most jewelers refer to GIA's professional color scale that begins with the highest rating of D for colorless, and down the alphabet to grade stones with traces of very faint or light yellowish or brownish color. The color scale continues all the way to Z.
Diamonds which are graded D through F are naturally the most valuable and desirable because of their rarity. But you can still obtain very attractive diamonds that are graded slightly less than colorless. And diamonds graded G through I show virtually no color that is visible to the untrained eye. And while a very, very faint tint of yellow will be apparent in diamonds graded J through M, this color can often be minimized by carefully selecting the right jewelry in which to mount your diamond. Keep in mind that,
while most people strive to buy the most colorless diamond they can afford, there are many people who actually prefer the warmer glow of lower-color diamonds.
Diamonds which are graded D through F are naturally the most valuable and desirable because of their rarity. Although diamonds that are graded slightly less than colorless. And diamonds graded G through I show virtually no color that is visible to the untrained eye.
And while a very, very faint tint of yellow will be apparent in diamonds graded J through M, this color can often be minimized by carefully selecting the right jewelry piece.
If you think about the incredible amount of pressure it takes to create a diamond and the fact that natural diamonds are not grown in a sterile laboratory; it's no surprise that most diamonds have flaws. Basically there are two types of flaws: inclusions and blemishes. Inclusions refer to internal flaws and blemishes refer to surface flaws, however, in the diamond grades listed below,
you'll note that none of the grades include the term "blemish".
For the purposes of grading diamonds, all flaws are called "inclusions". Inclusions include flaws such as air bubbles, cracks, and non-diamond minerals found in the diamond. Blemishes include scratches, pits, and chips. Some blemishes occur during the cutting processes. Diamonds with no or few inclusions and blemishes are more highly valued than those with less clarity
because they are rarer. Diamonds are graded for clarity under 10x loupe magnification.
Grades range from:
F - Flawless (free of blemishes & inclusions) to I - Included ( large, heavy blemishes and inclusions ) These clarity grades are:
|F:||Flawless: No internal or external flaws. Extremely rare.|
|IF:||Internally Flawless: no internal flaws, but some surface flaws. Very rare.|
Very Very Slightly Included (two grades). Minute inclusions very difficult to detect under
10 x magnifications by a trained gemologist.
|VS1-VS2:||Very Slightly Included. Minute inclusions seen only with difficulty under 10x magnification.|
|SI1-SI2:||Slightly Included. Minute inclusions more easily detected under a 10 x magnifications.|
|I1-I2-I3:||Inclusions visible under 10x magnification as well as to the human eye.
We do not recommend buying diamonds in any of these grades.
While the presence of these clarity characteristics lowers the clarity grade of a diamond, they can also be viewed as proof of a diamond's identity. GIA certificates include what is known as a "plot" of a diamond's inclusion, think of it as a "diamond fingerprint". Since no two diamonds are exactly the same, comparing the uniqueness of your diamond's clarity characteristics with the "plot" provided on the diamond certificate offers assurance that the diamond you pay for is the same diamond you receive.
While Flawless diamonds are the rarest, a diamond does not have to be flawless to be stunning. In fact, until you drop to the "I" grade, a diamond's clarity grade has an impact on the diamond's value, not on the unmagnified diamond's appearance.
Diamonds with VVS and VS grades are excellent choices for both value and appearance. More affordable (and still a great choice) are those diamonds which gemologists call "eye-clean" diamonds with no inclusions visible to the naked eye. These diamonds are SI1 and SI2 and unless the recipient carries a 10X Loup (a strong jewelry magnifying glass), they won't see the inclusions.
The quality of the "cut" makes difference in how a diamond looks. Diamond cut is perhaps the most important of the four C's. It is important to understand how this quality affects the properties and values of a diamond. A good cut gives a diamond its brilliance, which is that brightness that seems to come from the very heart of a diamond. The angles and finish of any diamond are what determine its "fire" and brilliance.
As shown in the images below, when a diamond is well-cut, light enters through the table and travels to the pavilion where it reflects from one side to the other before reflecting back out of the diamond through the table and to our eye. This light is the brilliance we mentioned, and it's this flashing, fiery effect that makes diamonds so mesmerizing.
In poorly cut diamonds, the light that enters through the table reaches the facets and then leaks out from the sides of the diamond rather than reflecting back to the eye. Less light reflected back to the eye means less brilliance.
Fluorescence is an effect that is seen in some gem-quality diamonds when they are exposed to long-wave ultraviolet light. Under most lighting conditions, this fluorescence is not detectable to the eye, and while most gemologists prefer diamonds without this effect, some people enjoy it. It's really just a matter of aesthetics.
Most gemologists agree that the best cut diamonds are those that follow a set of formulae calculated to maximize brilliance. These formulae can be seen in a diamond's proportions, most importantly how the depth compares to the diameter, and how the diameter of the table compares to the diameter of the diamond. However, the variance in the proportions between an Ideal Cut and a Poor Cut can be difficult to detect to the casual observer. Because cut is so important, several grading methods have been developed to help consumers determine the cut of a particular diamond.
In general, These grades are:
This cut is intended to maximize brilliance, and the typically smaller table sizes
of these diamonds have the added benefit of creating a great deal of dispersion
or 'fire' as well. These diamonds are truly for the person who enjoys knowing that he has one of the finest things that money can buy. This category applies only to round diamonds.
These diamonds reflect most of the light that enters them, creating a good deal
of brilliance. With these diamonds, the cutters have chosen to stray slightly from
the preferred diamond proportions in order to create a larger diamond. The result is that these diamonds fall slightly outside of some customers' preferences in terms
of, for example: table size or girdle width, though, in many cases many of the parameters of diamonds in this range will overlap with certain parameters of diamonds in the Ideal/Excelent ranges. Generally, the price of these diamonds in slightly below that of Premium Ideal/Excellent cuts.
|Good:||Diamonds that reflect much of the light that enters them. Their proportions fall outside of the preferred range because the cutter has chosen to create the largest possible diamond from the original rough crystal, rather than cutting extra weight off to create a smaller Premium quality diamond. Diamonds in this range offer an excellent cost-savings to customers who want to stay in a budget without sacrificing quality or beauty.|
|Fair / Poor:||A diamond graded as fair or poor reflects only a small proportion of the light that enters it. Typically these diamonds have been cut to maximize the carat weight over most other considerations. When we speak of a diamond's clarity, we are referring to the presence of identifying characteristics on (blemishes) and within (inclusions) the stone.|
Selecting the grade of cut is really a matter of preference. To make the best selection, you need to understand the various grades. The descriptions above are general guidelines for making your best selection.