A lot of you have probably heard of 4 cs of diamonds, but you may have some unanswered questions. Why is color a factor when diamonds look colorless? Can you clarify clarity? What kinds of cuts are there? And what is the difference between carat, karat, and carrot?
Today, we’re hoping to shed some light on the mysteries of the diamond grading process. Understanding the 4 cs of diamonds empowers consumers to make informed decisions and select diamonds that align with their desires and expectations.
Diamond Color Grade
Let’s start with color, or more precisely, the lack thereof.
As one of the 4 Cs of diamonds, diamonds come in a variety of colors but are largely grouped into two grading categories: the D to Z scale, which grades the colorlessness of a diamond, and fancy diamonds, which have more intense or rare colors.
On the D to Z scale, the less color present in the stone, the higher the value, with D representing the most colorless diamond. This scale doesn’t start with A because the Gemological Institute of America (GIA) wanted to differentiate it from earlier, more vague grading systems.
Some dealers used ABC123 or A double A and AAA as grading terminology, with no uniformity from dealer to dealer. Others used archaic descriptions such as blue-white or top light brown. So, GIA decided to start their scale at D to separate itself from all other grading systems being used, and it worked.
On the D to Z scale, all diamonds aren’t colorless. Most have some yellow or brown color present.
The grades D to F and G to J are graded as colorless and near-colorless, respectively, but the amount of yellow or brown present is described as faint for grades K to M, very light for grades N to R, and light for grades S to Z. This subtle difference in color can make a huge difference in the value of a diamond.
Diamond graders compare the stone being evaluated against a set of professionally graded master stones that represent the various color grades from colorless to light. Some diamonds appear colorless but have hidden color within them. They can actually fluoresce under ultraviolet light.
Some diamonds glow a different color, with blue being the most common. Others can appear white, orange, or yellow under UV light. Some diamonds that fluoresce very strongly can appear a bit cloudy or oily, which can lower the value of the stone.
On the other hand, some slightly yellow diamonds can appear more colorless in sunlight due to their fluorescence, so it can be a good thing too.
Diamond Clarity Grades
Next, we have clarity. As one of the 4 Cs of diamonds, this refers to how obvious the inclusions and blemishes of a stone are under 10 times magnification using a standard 10-power triplet loop.
The clarity grades, like the color grades, are largely divided into how noticeable the grade-setting feature is. Starting with the lower and most abundant clarity grade, we have three included grades: I1, I2, and I3, where the inclusions are obvious and may have a significant effect on transparency and brilliance.
By the way, the number one designates the best grade in its category for all grades.
Next, we have two slightly included grades: SI1 and SI2, where the inclusions are just noticeable under magnification.
VS1 and VS2 designate diamonds that are very slightly included, so much so that it takes some effort for a skilled grader to even find the imperfections. VVS1 and VVS2 are likely the best diamonds a vendor will have in stock. These diamonds are so very, very slightly included that it is difficult for a skilled grader to even find the grade-setting feature.
Internally Flawless Diamond
Finally, we come to IF or internally flawless. As one of the 4 Cs of diamonds, FL or flawless internally flawless diamonds have no imperfections inside the diamonds but will have some blemishes on the surface.
Flawless diamonds are exactly what they say they are, under 10 times magnification. When you’re out shopping, you may hear stones described as “eye clean.” While that isn’t technically a grade, it means that while there may be inclusions in the stone, they can’t be seen without magnification. These typically start at the grade SI1 and better grades.
You may also find a stone graded as SI3. Now, this isn’t a legitimate grade on the GIA clarity scale, but will likely be referring to a stone that is a very nice I1 stone with an obvious inclusion that nonetheless has little impact on the beauty of the diamond.
Diamond Cut Types
Next, let’s talk about cut.
As one of the 4 Cs of diamonds, there are many different shapes and styles of cut, like emerald cuts, old mine cuts, princess cuts, and round brilliants. The style of cut chosen will determine many of the diamond’s optical qualities, like its brilliance and dispersion.
The cut grade, while being the C that fewer people are familiar with, is just as important as any of the others. It is also the only grade affecting the value that is due solely to human ingenuity.
Round Brilliant Diamond
A round brilliant diamond, for example, is cut with very specific angles that differ from other gemstones. The cut of a round brilliant is designed to let the light enter the top of the diamond in the crown, bounce the light around inside the bottom of the stone on the pavilion, then exit back out the top of the diamond.
The more light that returns out of the crown, the more brilliant the diamond is. The longer the light reflects inside the diamond, the more fiery the diamond will be. Fire refers to the rainbow spectral colors that are seen in diamonds. This is caused by the separating of white light into its rainbow colors.
Cut also affects the scintillation of the diamond.
This is the movement of light and the pattern of light and dark in the diamond. Much study has gone into developing perfect cuts for diamonds. Proportions and symmetry are very important to this.
The diamond cut grade takes into account brilliance, fire, symmetry, proportions, facet arrangement, and even the polish of the surface. The cut grade ranges from poor to excellent, with ranks like fair, good, and very good in between. Each grade has a significant effect on the value of the diamond.
Diamond Carat Weight
Our last C is carat weight, which is the most objective of all.
Just weigh a diamond. The term “carat” comes from the practice of using carob seeds, which were small and very uniform, as a counterweight for measuring gemstones on a balanced scale.
Carat refers to the weight of the diamond. A diamond’s carat weight, along with its proportions, influences how large the stone will appear to face up. A carat is equivalent to one-fifth of a gram or 200 milligrams. Each carat is then divided into 100 points, representing the percentile weight of the carat to two decimal places.
Therefore, a half-carat stone may be expressed as half-carat, 0.50 carat, or 50 points.
Because ideal conditions must exist to produce larger, as well as clearer and more colorless diamonds, carat weight has a large effect on the value of the diamond. Much larger diamonds are increasingly more valuable.
The effect of diamond weight on price isn’t linear. That is, a one-carat diamond is worth more per carat than two half-carat diamonds, say a little over two times the amount per carat. By the time the same quality of the diamond is five carats, it would be worth almost 12 times the amount per carat.
That said, bigger isn’t always better. It’s important to remember that when grading diamonds, all four Cs have to be taken into consideration together. You wouldn’t want a dull, yellowish diamond just because it’s several carats, right?
When shopping for diamonds, most diamonds will have their price expressed in two ways: the per carat price and the final total price of the diamond based on the weight. Some weights have more of an effect on the value of a diamond. Significant price jumps occur at half-carat, three-quarter-carat, and full-carat sizes. Diamonds as little as one point below these magic sizes can be significantly less per carat.
Conclusion On 4 cs of diamonds
Hopefully, we were able to answer some of your questions and teach you a little bit about what can be a pretty mysterious industry. The 4 Cs of diamonds—carat weight, cut, color, and clarity—form the foundation for evaluating the quality and value of a diamond. Each C contributes to the overall beauty, brilliance, and desirability of a diamond, and understanding their significance is essential when making a diamond purchase.
