4 “C’s” for Diamond

What Are the 4 Cs of Diamonds?

You’ve probably heard about the 4Cs of a diamond, and you may even know that it stands for diamond cut, color, clarity and carat weight. Below we take a closer look into the individual 4Cs.

engagement ring

Cut

Of all the 4Cs, diamond cut has the greatest effect on a diamond’s beauty. In determining the quality of the cut, the diamond grader evaluates the cutter’s skill in the fashioning of the diamond. The more precise the diamond is cut, the more captivating the diamond is to the eye.

Learn more about diamond cut grading. 

Color

The color of gem-quality diamonds occurs in many hues. In the range from colorless to light yellow or light brown. Colorless diamonds are the rarest. Other natural colors (blue, red, pink for example) are known as “fancy,” and their color grading is different than from white colorless diamonds.

Learn more about diamond color grading.

Scattered Diamonds On A Black Background.
Close up of a diamond

Clarity

Diamonds can have internal characteristics known as inclusions or external characteristics known as blemishes. Diamonds without inclusions or blemishes are rare; however, most characteristics can only be seen with magnification.

Learn more about diamond clarity and how it is determined.

Carat

The carat is the diamond’s physical weight measured in metric carats. One carat equals 1/5 gram and is subdivided into 100 points. Carat weight is the most objective grade of the 4Cs.

Learn more about diamond carat weight. 

Diamond held in tweezers with more diamonds out of focus
Engagement Ring Proposal

The Fifth C: Confidence

When you shop smart with an American Gem Society jeweler, you will feel confident in your decision. You know that the jeweler is qualified to describe the characteristics of your diamond, so you can make the informed choice that is right for you.

Ready to buy? We can help! Learn more about diamond buying.


WHAT IS DIAMOND CLARITY?

Diamond Clarity Refers to the Absence of Inclusions and Blemishes

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To understand diamond clarity, we must first understand how diamonds are created. Natural diamonds are the result of carbon exposed to tremendous heat and pressure deep in the earth. This process can result in a variety of internal characteristics called ‘inclusions’ and external characteristics called ‘blemishes.’

Evaluating diamond clarity involves determining the number, size, relief, nature, and position of these characteristics, as well as how these affect the overall appearance of the stone. If you are trying to determine what is the best clarity for a diamond, remember that no diamond is perfectly pure. But the closer it comes to purity, the better its clarity. 

The GIA Diamond Clarity Scale has 6 categories, some of which are divided, for a total of 11 specific grades.

  • Flawless (FL) No inclusions and no blemishes visible under 10x magnification
  • Internally Flawless (IF) No inclusions visible under 10x magnification
  • Very, Very Slightly Included (VVS1 and VVS2) Inclusions so slight they are difficult for a skilled grader to see under 10x magnification
  • Very Slightly Included (VS1 and VS2) Inclusions are observed with effort under 10x magnification, but can be characterized as minor
  • Slightly Included (SI1 and SI2) Inclusions are noticeable under 10x magnification
  • Included (I1, I2, and I3) Inclusions are obvious under 10x magnification which may affect transparency and brilliance

DIAMOND CUT

Understanding Diamond Cut

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Diamonds are renowned for their ability to transmit light and sparkle so intensely. We often think of a diamond’s cut as shape (round, heart, oval, marquise, pear), but what diamond cut actually does mean is how well a diamond’s facets interact with light. Precise artistry and workmanship are required to fashion a stone so its proportions, symmetry and polish deliver the magnificent return of light only possible in a diamond.

Achieving the best cut for a diamond reflects in the stone’s final beauty and value. And of all the diamond 4Cs, it is the most complex and technically difficult to analyze. To determine the cut grade of the standard round brilliant diamond – the shape that dominates the majority of diamond jewelry – GIA calculates the proportions of those facets that influence the diamond’s face-up appearance. These proportions allow GIA to evaluate what the best cut for a diamond is, by studying how successfully a diamond interacts with light to create desirable visual effects, such as:

  • 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

DIAMOND CARAT WEIGHT

Diamond Carat Weight Measures a Diamond’s Apparent Size

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To put it simply, diamond carat weight measures how much a diamond weighs. 

A metric “carat” is defined as 200 milligrams. Each carat is subdivided into 100 ‘points.’ This allows very precise measurements to the hundredth decimal place. A jeweler may describe the weight of a diamond below one carat by its ‘points’ alone. For instance, the jeweler may refer to a diamond that weighs 0.25 carats as a ‘twenty-five pointer.’ Diamond weights greater than one carat are expressed in carats and decimals. A 1.08 carat stone would be described as ‘one point oh eight carats.’

All else being equal, diamond price increases with diamond carat weight because larger diamonds are rarer and more desirable. However, two diamonds of equal carat weight can have very different values (and prices) depending on three other factors of the diamond 4Cs: Color, Clarity, and Cut.

While now you know what carat means, it’s also important to remember that a diamond’s value is determined using all of the 4Cs, and not just carat weight.



Diamond Color Actually Means Lack of Color

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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. A chemically pure and structurally perfect diamond has no hue, like a drop of pure water, and consequently, a higher value. GIA’s D-to-Z diamond color-grading system measures the degree of colorlessness by comparing a stone under controlled lighting and precise viewing conditions to masterstones of established color value.

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.

This short video explains the GIA color scale and how GIA classifies a diamond with a letter grade from D-to-Z by comparing it to masterstones representing the color grades on the GIA scale.

WHY DOES THE GIA COLOR GRADING SYSTEM START AT D?

Before GIA universalized the D-to-Z Color Grading Scale, there was no clear standard to define what diamond color is. A variety of other systems were used loosely, from A, B, and C (used without clear definition), to Arabic (0, 1, 2, 3) and Roman (I, II, III) numbers, to descriptive terms like “gem blue” or “blue white,” which are notorious for misinterpretation. So, the creators of the GIA Color Scale wanted to start fresh, without any association with earlier systems. Thus the GIA scale starts at the letter D. Very few people still cling to other grading systems, and no other system has the clarity and universal acceptance of the GIA scale.

ARE DIAMONDS GRADED AS ZsCONSIDERED FANCY-COLOR?

No. Naturally colored diamonds outside the normal color range are called fancy-color diamonds. The FTC provides no guidelines for the use of the term “fancy-color” in the US, but there is general agreement in the international trade about what diamond color range is customary for fancy-color diamonds. These are either yellow or brown diamonds that have more color than a Z master stone or they exhibit a color other than yellow or brown.