The 4C's of Diamond Quality
Jewelry professionals use a systematic way to evaluate and discuss the factors involving the quality of a diamond. Otherwise, there would be no way to compare one diamond to another. And there would be no way to evaluate and discuss the qualities of an individual diamond.
Diamond professionals use the grading system developed by GIA in the 1950s, which established the use of four important factors to describe and classify diamonds: Clarity, Color, Cut, and Carat Weight. These are known as the 4Cs. When used together, they describe the quality of a finished diamond. The value of a finished diamond is based on this combination.
DIAMOND GRADING CHART
Diamond Color Actually Means Lack of Color
Understanding what diamond color means helps in choosing the right diamond. Interestingly, the diamond color evaluation of most gem-quality diamonds is based on the absence of color. Diamond color is the hue of a diamond based on the GIA diamond color scale, which grades the diamond’s color on a spectrum of D (colorless) to Z (light yellow hue). The absence of color is what determines both its grade and value, as well as has a significant impact on its appearance. Diamond color grade is typically determined with the diamond face down and the culet facing up against a pure white surface, following a grading scale of D (colorless) to Z (faint yellow).
Many of these diamond color distinctions are so subtle that they are invisible to the untrained eye; however, these distinctions make a very big difference in diamond quality and price. Hence, it is important to get a GIA expert’s opinion in evaluating the best color for your diamond.
GIA COLOR SCALEThe GIA D-to-Z scale is the industry standard for color-grading diamonds. Each letter represents a range of color based on a diamond’s tone and saturation.
DIAMOND GRADESCOLORLESS DIAMONDS: The rarest and highest quality with a pure icy look.
- D-F Color Diamonds
NEAR-COLORLESS DIAMONDS: No discernible color; great value for the quality.
G-H Color Diamonds
I-J Color Diamonds
- K Color Diamonds
** Helpful Hint ** Diamond prices decline or increase in alphabetical order. For example, a diamond with a G color grade is less expensive than a diamond with a D color grade.
ABOUT DIAMOND COLOR
Subtle differences in color can dramatically affect diamond value. Two diamonds of the same clarity, weight, and cut can differ in value based on color alone. Even the slightest hint of color can make a dramatic difference in value.
Diamonds come in many colors. Diamonds that range from colorless to light yellow and brown fall within the normal color range. Within that range, colorless diamonds are the most rare, so they’re the most valuable. They set the standard for grading and pricing other diamonds in the normal color range.
At the GIA Laboratory, diamonds are color graded under controlled conditions by comparing them to round brilliant diamonds of known color, called masterstones.
Blue is the most common fluorescent color in gem-quality diamonds. In rare instances, fluorescence can be white, yellow, orange, or many other colors.
Strong blue fluorescence can make a light yellow diamond look closer to colorless in sunlight. Blue and yellow are color opposites and tend to cancel each other out, so blue fluorescence masks the yellow color. If the fluorescence is too strong it can make the stone look cloudy or “oily,” which can lower the value of the diamond.
Diamond Clarity Refers to the Absence of Inclusions and Blemishes
GIA DIAMOND CLARITY SCALE
- Flawless (FL) No inclusions and no blemishes visible under 10x magnification
- No internal or external characteristics
- Less than 1% of all diamonds are FL clarity
- A flawless diamond is incredibly rare because it’s nearly impossible to find a diamond 100% free of inclusions
- Internally Flawless (IF) No inclusions visible under 10x magnification
- Some small surface blemishes may be visible under a microscope on IF diamonds
- IF diamonds have no inclusions within the stone, only surface characteristics set the grade
- Visually eye clean
- Very, Very Slightly Included (VVS1 and VVS2) Inclusions so slight they are difficult for a skilled grader to see under 10x magnification
- VVS clarity is rare and results in an eye clean appearance
- Very Slightly Included (VS1 and VS2) Inclusions are observed with effort under 10x magnification, but can be characterized as minor
- Minor inclusions ranging from difficult (VS1) to somewhat easy (VS2) to see at 10x magnification
- Great value; Devon's Diamonds & Decor's most popular diamond clarity
- Slightly Included (SI1 and SI2) Inclusions are noticeable under 10x magnification
- If eye clean, SI diamonds are often the best value
- SI2 inclusions may be detectable to a keen unaided eye, especially when viewed from the side
- Included (I1, I2, and I3) Inclusions are obvious under 10x magnification which may affect transparency and brilliance
- Devon's Diamonds & Decor does not sell I clarity grade diamonds in their jewelry
( NO INCLUSIONS )
“Flawless” diamonds are flawless inside and out. At 10X magnification under a microscope, they have no visible blemishes or inclusions. (If a diamond has inclusions too small to see at this magnification, they have no effect on the clarity grade).
“Internally flawless” means that the stone has blemishes but no inclusions. Blemishes encompass things like scratches and nicks that exist only on the external diamond surface. Usually, they can be polished away and likely won’t affect the clarity grade too much. On the other hand, inclusions like crystals and feathers (cracks) exist inside the stone. These have much more impact on the clarity grade.
Incredibly rare, flawless and internally flawless stones account for just 2% of gem-grade diamonds. Thus, they command high prices, especially in large carat sizes.
You’ll find an enormous price difference between an F and an IF stone, like that between an IF and a VVS stone. As clarity grades go down, the price differences decrease exponentially.
Very Very Slightly Included (VVS) Diamonds
( MINUTE INCLUSIONS )
VVS stones have minute inclusions, so small they’re barely noticeable under 10X magnification. Most consumers likely can’t tell the difference between F, IF, and VVS diamonds.
Any stone in the VVS range still has extremely high clarity and will command a premium price.
Very Slightly Included Diamonds
( MINOR INCLUSIONS )
VS stones occupy the upper-middle range of diamond clarity grades. They have minor inclusions, which means they don’t interfere much with clarity, even though they’re larger or more numerous than those in VVS stones.
Slightly Included Diamonds
( NOTICEABLE INCLUSIONS )
Stones in the SI range drop into commercial-quality. The inclusions are noticeable at 10X magnification but most likely not with the naked eye. Still, an SI stone may appear cloudier and less brilliant, especially to someone familiar with fine jewelry.
( OBVIOUS INCLUSIONS )
Generally, buying I stones isn’t a good idea, even though they’re technically gem quality. I diamonds have inclusions obvious even to the naked eye. Furthermore, these inclusions may even affect the diamond’s durability or wearability, especially I3 stones.
Understanding Diamond Cut
Brightness: Internal and external white light reflected from a diamond
Fire: The scattering of white light into all the colors of the rainbow
- Scintillation: The amount of sparkle a diamond produces, and the pattern of light and dark areas caused by reflections within the diamond
The GIA Diamond Cut Scale
ANATOMY OF A DIAMOND
DIAMOND CARAT WEIGHT
Diamond Carat Weight Measures a Diamond’s Apparent Size
The term carat is often misunderstood. It refers to a diamond's weight, not its size. Another misperception is that a larger carat weight is always better than a smaller carat weight. While it’s true that a big rock can be a status symbol, carat weight is not related to sparkle. Beautiful sparkle is the result of a well-crafted cut. In fact, a high carat weight diamond with a poor cut may look smaller than a diamond with a smaller carat weight and a very good cut.
Diamond weights are stated in metric carats, abbreviated “ct.” One metric carat is two-tenths (0.2) of a gram—just over seven thousandths (0.007) of an ounce. One ounce contains almost 142 carats. A small paper clip weighs about a carat.
The metric carat is divided into 100 points. A point is one hundredth of a carat.
Diamonds are weighed to a thousandth (0.001) of a carat and then rounded to the nearest hundredth, or point. Fractions of a carat can mean price differences of hundreds—even thousands—of dollars, depending on diamond quality.
Over a carat, diamond weights are usually expressed in carats and decimals. A 1.07-carat stone, for example, would be described as “one point oh seven carats,” or “one oh seven”. Weights for diamonds that weigh under a carat are usually stated in points. A diamond that weighs 0.62 carat is said to weigh “sixty-two points,” or called an “sixty-two pointer.”
The relationship between rarity, weight, and value can be surprising. People know that a pound of sugar costs twice as much as a half-pound of sugar. But diamonds aren’t a commodity like sugar. Their price depends on a number of variables—weight is just one of them. So it’s not always easy to understand, or explain, why a 1-carat diamond is worth, say, $6,000, while a 2-carat diamond of similar quality might be worth $15,000.
All else being equal, diamond price increases with carat weight, because larger diamonds are more rare and more desirable. But two diamonds of equal carat weight can have very different values (and prices) depending on three other factors within the 4Cs: Clarity, Color, and Cut. It's important to remember that a diamond's value is determined using all of the 4Cs, not just carat weight.
TOTAL CARAT WEIGHT
Understanding diamond terminology is essential if you’re going to make a smart purchase decision. “Total carat weight” (abbreviated tcw) is the combined weight of all the diamonds in a piece of jewelry that only contains diamonds.
For example, an engagement ring set with many small melee diamonds weighing 2.15 tcw will cost significantly less than a solitaire engagement ring set with a single 2.15 ct diamond. Again, think size/rarity/price.
If an engagement ring has gems other than diamonds in it, the combined weight of all the stones is called “total gem weight.”