What Are the 4Cs of Diamonds?

The 4Cs of diamonds—Cut, Color, Clarity, and Carat—serve as the global standard for evaluating a diamond’s quality and value. This grading system was established by the Gemological Institute of America (GIA) in the 1940s to create a consistent way to assess diamonds. Each of these key qualities is clearly listed on a diamond grading report, offering a reliable summary of the stone’s characteristics.

On this page

Beyond the 4Cs of Diamonds

When choosing a natural diamond engagement ring, the most important factor is selecting a diamond that truly resonates with you. While the 4Cs of diamonds—Cut, Color, Clarity, and Carat—serve as helpful guidelines in evaluating a diamond’s quality, they should never overshadow the emotional connection you feel with your stone. Natural diamonds are formed over billions of years deep within the Earth’s mantle, undergoing immense heat and pressure that shape their one-of-a-kind characteristics. As a result, many natural diamonds carry unique inclusions or blemishes, which are tiny internal features that make each stone distinct.

These natural markings serve as small time capsules, offering a glimpse into the extraordinary journey a diamond has taken from deep within the Earth to become a cherished symbol of love. Rather than imperfections, these inclusions tell a story of age, authenticity, and rarity, making each natural diamond as unique as the person who wears it. A diamond’s true value lies not just in its grading and technical qualities, but in the personal connection it evokes and the sentiment it holds for a lifetime.

Diamond Clarity Chart

The clarity grade of diamonds refers to the absence of inclusions or blemishes. The clarity scale ranges from Flawless (FL) to Included (I). Natural diamonds that form without any inclusions are extremely rare and deemed internally flawless on most grading scales. These rare diamonds are some of the most valuable in the world.

Why It Matters: A diamond’s clarity affects how clean and brilliant it looks, especially under magnification or close inspection.

Learn more

1. Flawless
(FL)

No inclusions or blemishes visible under 10x magnification.

2. Internally Flawless
(IF)

No inclusions or blemishes visible under 10x magnification.

3. Very, Very Slightly Included
(VVS1, VVS2)

Minute inclusions are difficult to detect even under magnification.

4. Very Slightly Included
(VS1, VS2)

Inclusions are minor and difficult to detect under 10x magnification.

5. Slightly Included
(SI1, SI2)

Inclusions are visible under magnification and may be visible to the naked eye in SI2.

6. Included
(I1, I2, I3)

Inclusions are visible to the naked eye and may affect the diamond’s appearance and durability.

J Color

Slightly more visible color, especially in larger stones.

I Color

Some noticeable tint in larger diamonds.

H Color

Slight warmth but still appears white in most lighting.

G Color

A slight hint of color, nearly indistinguishable to the naked eye.

F Color

Also nearly colorless, with a barely perceptible difference from E.

E Color

Nearly colorless, with only microscopic traces of color detectable by experts.

D Color

Completely colorless and the most valuable.

Diamond Color Scale

A natural diamond’s color grade is usually a measure of how colorless the diamond is. Most natural diamonds appear colorless or near colorless to the average shopper, but actually have slight tints of yellow or brown. The closer the stone is to a colorless diamond, the rarer and generally more valuable it is.

Natural diamonds are graded on a color scale ranging from D (colorless) to Z (heavily tinted brown or yellow). Diamonds typically begin to show a noticeable light yellow tint starting at the K grade on the GIA color scale.

Diamonds can also form naturally in almost any color imaginable because of factors apparent in the earth when they form. Most of these natural colored diamonds are so rare that their value can be limitless, and they are graded on a different scale more closely describing the visible color.

Why It Matters: A diamond’s color can impact its overall appearance and price, especially in certain shapes or larger stones where color is more noticeable.

Learn more

Diamond Cut Grade

Not to be confused with diamond shape, the cut of a natural diamond determines how it interacts with light. The Cut Grading System assesses a diamond’s appearance, including its brightness, fire, and scintillation, which make up the way a diamond reflects light, dispersing it into color, and sparkles.

Cutting a natural diamond requires a perfect balance of artistry and precision to enhance its brilliance. This is why a diamond’s cut grade not only measures how well it reflects light but also evaluates the craftsmanship behind its proportions, polish, and symmetry. Ranging from Excellent to Poor, cut grade is considered the most important factor influencing a diamond’s overall beauty and value.

The GIA (Gemological Institute of America) and other grading organizations use the round brilliant diamond as the benchmark for evaluating cut quality because it has the most precise and universally recognized proportions.

Why It Matters: A diamond’s cut has the biggest impact on its sparkle and brilliance, more than any other of the 4Cs of diamonds.

Learn more

GIA Diamond Cut Grade Scale

Poor

A poorly cut diamond that appears dull and lacks fire due to excessive light loss.

Fair

Still offers a decent amount of sparkle, but some light leakage occurs, reducing overall brightness.

Good

Still offers a decent amount of sparkle, but some light leakage occurs, reducing overall brightness.

Very Good

Nearly as brilliant as Excellent, with only slight differences in light performance that are difficult to detect.

Excellent

The highest cut grade, offering maximum brilliance, fire, and scintillation. Light is reflected efficiently, creating the most dazzling effect.

Cut Characteristics

Table

The table is the top horizontal facet of the diamond.

Crown

The crown height is the upper portion of the diamond.

Girdle

The girdle is the middle portion of a diamond.

Pavilion

Pavilion angle is an important dimension of the stone

Culet

The small facet at the bottom of a diamond to prevent chipping and abrasion to the point.

Depth

The diamond’s overall depth from the surface of the table to the culet.

Diamond Cut Chart

Shallow Proportions

Poor brilliance and light performance

Ideal Proportions

Most brilliant. Optimal light performance

Deep Proportions

Poor brilliance and light performance

Diamond sizes shown are for visual reference only and are approximate. Actual sizes may vary.

Diamond Carat Weight

The carat of a natural diamond is the measurement of its weight. One carat is equivalent to 200 milligrams, or 0.2 grams. Carat weight is often used as an indicator of a diamond’s size, though two diamonds of the same carat weight can appear different in size depending on their shape and how they are cut.

Natural diamonds one carat and larger are becoming increasingly rare, as global supply continues to decline and only one significant deposit has been discovered in decades. In fact, the annual global recovery of all natural diamonds one carat and larger could fit inside just one exercise ball.

Why It Matters: Carat weight influences a diamond’s size—and its price—but bigger isn’t always better. Cut and proportions play a major role in visual impact.

Learn more

FAQs: 4Cs of Diamonds

What is the most important of the 4Cs of diamonds when buying a ring?

Of the 4Cs of diamonds—Cut, Color, Clarity, and Carat—cut is often considered the most important. A well-cut diamond will sparkle more brilliantly, even if its color or clarity grade is slightly lower.

Is it worth buying a diamond with flawless clarity?

Not always. The 4Cs of diamonds help you evaluate trade-offs, and flawless clarity comes at a premium. Many diamonds with slightly lower clarity (like VS or SI grades) still appear eye-clean and offer better value.

Do all diamonds come with certification of the 4Cs?

No, not all diamonds come with an official report. It’s essential to choose a diamond that has been evaluated by a trusted lab, such as GIA or AGS, to confirm its 4Cs of diamonds and authenticity.

What’s the difference between diamond shape and the “cut” in the 4Cs of diamonds?

Diamond shape refers to the outline (such as round, oval, or emerald), while cut—as defined in the 4Cs of diamonds—measures how well the stone is faceted and proportioned to maximize brilliance.

How do I balance the 4Cs of diamonds within my budget?

The key to choosing the right diamond is understanding which of the 4Cs of diamonds matter most to you. For example, if sparkle is your priority, focus on cut. If size is most important, you may want to prioritize carat and compromise slightly on clarity or color. Knowing what you value helps you make smart trade-offs without sacrificing beauty.

About Natural Diamond Council

Natural Diamond Council (NDC) is the global authority on natural diamonds. As a not-for-profit organization, NDC is committed to advancing the integrity of the natural diamond industry and celebrating the unmatched beauty and value of natural diamond jewelry. NDC serves as the industry’s definitive voice, offering expert insight, trusted education, and unparalleled access to the world of real, rare, and responsibly sourced natural diamonds.

Natural Diamonds