Diamonds certainly come in a variety of sizes, colors, and shapes. All diamonds possess intricate combinations of characteristics that make them unique. Knowing how to choose the best diamond is important, especially prior to purchase.
The American Gem Society (AGS) notes, “After all, diamonds are expensive. You want assurance that the quality you’ve paid for is the quality you are getting.” Expert jewelers and appraisers possess the knowledge and experience needed to assess the quality of a diamond. Using a systematic rating system for specific characteristics, jewelers and expert graders can evaluate your diamond.
However, knowing a bit about diamonds prior to purchase is valuable to consumers. The good news is that you can use the same grading system professional jewelers and gem experts use.
These are known as the 4Cs. When all these elements are combined, they paint a perfect picture of the quality of your diamond.
The 4Cs of diamond quality are:
- Carat Weight (size)
All of the 4Cs are important, and when it comes to the quality of your diamond, all should be considered. And the certification your diamond holds is just as important.
Let’s take a closer look at five ways to check the quality of your diamond the way the experts do.
1. Carat Weight of Your Diamond
Carat weight is certainly the most objective of all the 4Cs. A calibrated digital scale measures a diamond’s carat weight. And weight is often associated with the quality and value of a diamond.
You may be familiar with fractional carat weight delineations for diamonds, such as one-quarter, one-half, one, etc., but carat weight is actually best represented using decimals. A diamond marked one carat in the store may actually have a carat weight of 0.89, a rounding practice commonly used in retail stores to make the value of a piece seem higher. But a 0.89 carat diamond should be significantly less expensive than a true one carat stone, all other factors being equal.
It is also essential to understand that not all carat weights are created equal. A two-carat diamond of lesser color, cut, and clarity could be less expensive than a one-carat of higher quality. Basically, this measurement of quality can give you a skewed perception of value. “Comparing the value of diamonds by carat weight is like comparing the value of paintings by size,” explains AGS.
Always consider the 4Cs, and not simply the weight when checking the quality of your diamond.
2. Color Quality of Your Diamond
The color quality of your diamond can have a big impact on its value. The perfect diamond is colorless, and any hint of color makes a colossal difference in the quality of your diamond. As you move down the color scale, tinges of yellow or brown appear in the stones, and this colored tint reduces the value and quality unless that color is judged to be a ‘fancy color’, like a canary yellow or the ultimate in rarity, a red diamond.
“Many of these color distinctions are so subtle as to be invisible to the untrained eye,” explains the Gemological Institute of America (GIA). “But these slight differences make a very big difference in diamond quality and price.”
A diamond’s color quality is assessed using a 23 color grading scale ranging from D to Z. Each letter corresponds with five subcategories of color quality.
Elements of the GIA diamond color grading scale are:
- Colorless (D-F)
- Near Colorless (G-J)
- Faint (K-M)
- Very Light (N-R)
- Light (S-Z)
As previously mentioned, the closer to colorless a diamond is, the higher the value and quality, but color is an exceedingly subjective member of the 4Cs. Surroundings when examining the color of a diamond can affect its color appearance. The setting and metal of the setting can also influence color. Women are also statistically more sensitive to color differences in diamonds than men.
An E color diamond on the left compared to an N color diamond on the right. The E color is extremely colorless, whereas the N color shows an obvious yellow tint.
The color quality of your diamond is certainly important. A four-carat diamond with an “S” color grade might be far less impressive than a one-carat colorless diamond. If you want to judge the color quality of a stone yourself, take a page from the professionals. Turn the diamond face down on a white sheet of paper in a well-lit room. This will help make any tint of color more apparent, and then you can decide what range you are most comfortable with when making your purchase. Just remember that while color is graded from the bottom, diamonds are viewed from the top, so consider the look of the entire stone before ruling out a color grade.
3. Clarity Rating of Your Diamond
The clarity rating of your diamond is another essential element to understand. A flawless diamond has no inclusions or surface imperfections, while a poor clarity quality will have inclusions that can be spotted by an unaided eye and may even have chips or other surface aberrations.
Why does clarity impact the quality and value of a diamond? AGS notes, “Clarity is considered important in the value of a diamond because of the notion that diamonds with a higher clarity are rarer in nature.” Not only is clarity an important characteristic in the rarity of a stone, but a diamond with a very low clarity grade will actually be less brilliant and might be prone to chipping, cracking, or even shattering.
Diamond clarity characteristics are graded while the diamond is being examined under 10x magnification. The clarity quality is then indicated using a clarity scale with 11 clarity grades. And these grades are important for you to understand.
Diamond clarity grades under 10x magnification include:
- Flawless (FL) diamonds have no inclusions or blemishes.
- Internally Flawless (IF) diamonds have no internal inclusions but may have slight surface blemishes.
- Very, Very Slightly Included (VVS1) and (VVS2) diamonds have minute inclusions difficult to see, even under magnification.
- Very Slightly Included (VS1) and (VS2) diamond have minor inclusions detected easily under magnification but not by the naked eye.
- Slightly Included (SI1) and (SI2) diamonds have noticeable inclusions under magnification that can be visible to an unaided eye.
- Included (I1), (I2), and (I3) diamonds have obvious inclusions easily visible to the naked eye with potential durability risk the further down the scale you go.
The SI2 emerald diamond on the left has a few visible black inclusions, whereas the VVS1 emerald on the right shows no visible inclusions for excellent clarity.
The easy standard to judge clarity on your own is the notion of an ‘eye clean’ diamond. This means that you cannot see any inclusions with the naked eye, and is usually the point at which most customers will feel they made a good purchase. You can always ask for a jeweler’s loupe to examine the stone under magnification, but it can be hard to judge clarity for a layperson. Just be sure that you view the diamond outside of the fancy lights in a jewelry store, as these lights are specifically designed to increase brilliance and to help hide visible clarity characteristics.
4. Cut Quality of Your Diamond
The cut quality of your diamond is of aesthetic importance. A well-cut diamond dazzles, as every angle and facet of your diamond interacts with light beautifully. For round diamonds, the cut quality is fairly objective, but judging cut quality of fancy shape stones (any shape other than a round) is a little bit more subjective.
“Keep in mind that a well-cut diamond will have more life and sparkle than one with a lesser cut quality,” according to AGS.
The perfect cut encompasses these three optical effects, making your diamond stunning:
- Brightness. This is the white light reflection of your diamond.
- Fire. Fire refers to the flashes of color your diamond displays as light refracts due to a prismatic effect.
- Scintillation. This factor is the play between the light and dark areas of your diamond.
The general idea of a quality cut is to have the perfect contrast between the light and dark areas of your diamond for that brilliant, sharp appearance.
The AGS and other reputable diamond graders use a 10-point cut quality scale, but different grading laboratories will use slightly different nomenclature. Knowing how your diamond’s cut is assessed is a vital element to understanding the quality of your diamond.
The cut quality for AGS grading ranges from:
- Ideal Cut (0)
- Excellent Cut (1)
- Very Good Cut (2)
- Good Cut (3 to 4)
- Fair Cut (5 to 7)
- Poor Cut (8 to 10)
The cut of a diamond is often confused with its unique, stunning shape. While cut is related to shape, as previously mentioned, the cut and the shape are not the same. Most people are familiar with the round brilliant cut diamond, but might be less familiar with the fancy shapes. The most well known fancy shapes are the princess, pear, cushion, emerald, oval, and marquise. Some of the lesser known main shapes are the Asscher, heart, and radiant.
The best way to judge cut quality of a diamond isn’t to use tools like the Holloway Cut Advisor, which is both outdated and horribly inaccurate, but is actually to view a diamond in person. There is no better judge of light performance than to see the light performance for yourself, and you will know immediately if you are happy with it or not. To get the best feel, examine the stone under different types of lighting, including indoors and natural light. Just remember, if there is poor external lighting, you can’t expect a lot of brilliance from the stone since diamonds don’t generate light on their own!
5. Diamond Certification
The 4Cs are certainly vital when you want to check the quality of your diamond. However, simply taking a jewelers word for it is not best practice.
A diamond certification is documentation of a diamond’s quality by a third party. This is not a certification by the diamond buyer or seller. These have become increasingly important due to diamond scams.
A radiant loose cut diamond shown along with its GIA certificate, which details the evaluation of the stone’s 4Cs by graders in a laboratory setting.
Diamond certificates feature various security features to ensure they are original. One or more of the most reputable diamond graders in the U.S. and Europe issues them.
The top diamond graders in the U.S. and Europe are:
- Gemological Institute of America (GIA)
- American Gemological Society (AGS)
- European Gemological Laboratory (EGL)
- Diamond High Council (HRD)
- International Gemological Institute (IGI)
- International Confederation of Jewelry, Silverware, Diamonds, Pearls, and Stones (CIBJO)
Ensuring your diamond has been certified by one of the above diamond graders is absolutely essential to checking its quality. GIA has a diamond “Report Check” you can utilize online. If a certificate is presented from any other grading entity, do some research to make sure it isn’t owned by the person selling you the stone. You want a truly independent report of the diamond’s quality.
In order to check the quality of your diamond, you must first know what to look for. A working knowledge of the 4Cs and a diamond accompanied by certification from a reputable gemological laboratory will ensure you get the facts.
With so many elements supporting a diamond’s true brilliance, one can never be too informed prior to making one of the most important purchases of a lifetime. For more information about diamond quality, visit Brilliance.com’s education section.