The 4 C's of Diamonds: Carat, Cut, Color & Clarity

The 4 C's are the major visual attributes of a diamond. They include Carat, Cut, Color and Clarity. These 4 characteristics are graded and categorized to identify the size and quality of the diamond. They also help is differentiating between similar diamonds and establishing the diamond's value and price.The grading scales for the 4 C's are established by the Gemological Institute of America or GIA. The standardized grading scale practices allow consumers and gemologists to accurately identify diamonds. Once you've mastered the 4 C's you'll be ready to effectively select a diamond that works within your price range and maximize the quality and size factors within that price. This guide will effectively educated you on the basics so you know what to look for and how to evaluate a diamond and its quality/value.

Carat: The Most Visual C - Size

Diamond carat is its weight and reflects the diamond’s size. The larger the diamond, the rarer and more valuable it becomes. Carat is the most visible C. Not to be confused with karat (a measure of gold purity), a 1.00 carat or ct diamond weighs 0.20 grams. The size of a diamond is measured in millimeters by length and width or in other words the diameter of the diamond. It typically takes about 250 tons of rock mining to produce just 1.00ct of diamond. That is why diamonds are rare and expensive.

Diamonds within each carat range have average millimeter sizes so you can approximate their visual size. Although each diamond is unique, these millimeter measurements are typically the norm, especially since diamonds today are cut with machines to ensure precision. To truly understand the diamond’s size, evaluate the measurements. Well cut Round diamonds have less depth than well cut fancy shaped diamonds (diamonds other than Round).

Loose round diamond carat scale by mm: .25ct, .50ct, .75ct, 1ct, 1.5ct, 2ct, 3ct, 4ct, & 5ct
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Diamond pricing increases exponentially, not linearly, as diamond carat weight increases. Once a diamond hits it’s critical weight, the price bumps up. The critical weights are: 0.30ct, 0.40ct, 0.50ct, 0.70ct, 0.90ct 1.00ct, 1.50ct, 2.00ct, 3.00ct, 4.00ct, 5.00ct, 10.00ct. Diamond cutters will do everything they can to keep the diamond weight at or above each critical weight.

The average diamond carat weight is 0.90ct. Consumers prefer Carat above the other C’s of diamonds because carat is the most visual C. When pricing diamonds, think about carat on one side and the other 3 C’s on the other side. In order to fit your diamond budget, as you increase carat, you may need to reduce the other C’s. Vice versa, if you increase the other C’s, you may need to decrease carat. See our Diamond Carat Guide for more in depth information.

Cut: The Diamond's Sparkle

Diamonds are cut to maximize the sparkle, fire, brilliance and overall visual beauty of a diamond. The cut is a measure of light performance as light hits a diamond. Diamonds sparkle is a result of light performance. As light hits a diamond, it penetrates the diamond, bounces around and reflects within the diamond and ultimately returns light to your eye. That is the sparkle that you see.The cutting of a diamond directly impacts the amount of light performance achieved. The angles, locations, sizes and shapes of facets will determine the diamond sparkle.

gia cut grading scale showing diamond light performance and sparkle from Excellent cut, Very Good cut, and Good cut

Fair & Poor: Diamonds with significant light leakage earn a Fair or Poor grade. These diamonds tend to leak noticeable amounts of light from being too deep or shallow in height. These have little brilliance and are less visually appealing. Fair or Poor cut diamonds do not meet With Clarity’s minimum light performance criteria. This cut category represents the top 35% of gem quality diamonds. Avoid these diamonds as they will not make for sparkling jewelry.

Very Good: Very well cut diamonds that capture almost all the potential of the diamond. Very brilliant with minimal light leakage. Diamonds cut often intentional cut to achieve a Very Good grade so that can improve the other characteristics of the diamond such as Color, Clarity or Carat. The top 15% of gemstone quality diamonds are Very Good cut. Very Good cut diamonds can be a great choice if looking mazimize value on the other factors.

Good: Well cut diamonds that capture light and possess high degrees of sparkle. Good cut diamonds have some light leakage, but overall shine bright. These diamonds can have noticeably larger or even smaller measurements than perfectly cut diamonds of the same shape. Cutters may intentionally cut to Good proportions to achieve a particular look or style. The top 25% of diamonds have a Good cut grade. Good cut diamonds can be a good blend of value and size, however be careful and always ask a gemologist to assess the particular diamond for you before you make a decision.

Excellent: The highest grade representing the top diamonds in the world. Diamonds with an Excellent cut grade are masterfully crafted and precisely cut to unleash the maximum sparkle and brilliance of a diamond. Little or no light leakage occurs as light passes through a diamond. This premium category represents the top 3% of all diamonds. Excellent cut diamonds are increasing with improvements in manufacturing technology. An excellent cut diamond is always a good choice regardless of diamond shape and size.

Cut is often consider the most important of the 4 C’s of diamonds (carat is more of a preference, not an art or science). When selecting a diamond, it will certainly important to ensure light is not lost. Excellent cuts are most premium and Very Good cuts offer more value. The differences in sparkle are quite subtle, but they are noticeable when compared side by side. We recommend maximizing on the Cut grade, if possible. See our Diamond Cut Guide for more in depth information.

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Color: Diamond's Shade or Tint

A diamond's color is the soft tint of shade of yellow/brown that is seen inside the diamond. All diamonds on the GIA D through Z scale are considered white although on the lower end they can have a tinge of yellow color. Color is a natural element in diamonds. The more yellow/brown the tint of color, the less the sparkle of the diamond because light performance/reflection is reduced. Color is essentially a visual distraction that affects sparkle. The grade is a representation of how much that color shade can be seen. Diamond color is grading by evaluating the body color of the diamond on a pure white background, face down. From face up, color is harder to identify.

the GIA color grading scale from D - L for round loose diamond
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Clarity: The Diamond's Unique Imperfections

During the diamond growth process, microscopic impurities or imperfections become present within the diamond. These imperfections are known as diamond inclusions. Inclusions are extremely common within diamonds and are essentially birthmarks that give every diamond uniqueness. The inclusions cummulatively make up the diamond's clarity. This clarity is measured by gemologists and graded on a scale. Diamonds range in clarity from FL - I3. Inclusions are examined at 10x magnification. See our Diamond Color Guide for more in depth information.

10x zoom magnified diamond example, typical for diamond clarity grading
10x zoom
10x zoom with I1 clarity inclusions
10x zoom with SI2 clarity inclusions
10x zoom with SI1 clarity inclusions
10x zoom with VS2 clarity inclusions
10x zoom with VS1 clarity inclusions
10x zoom with VVS2 clarity inclusions
10x zoom with VVS1 clarity inclusions
10x zoom with IF clarity inclusions
10x zoom with FL clarity inclusions

When evaluating the 4C's, clarity is the third most important characteristic because most imperfections cannot be seen unless under at least 10 times magnification. ( Cut is the most important 4C to consider). To maximize your budget, consider an SI quality diamond, knowing that it may have very slight inclusions visible to the naked eye if the stone is examined very closely. See our Diamond Clarity Guide for more in depth information.

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