The 4Cs of Diamonds: Cut, Color, Clarity and Carat, With the Grading Charts and What Each Grade Costs

By Cameron Malakan, owner of Clairamor and third-generation jeweler · Published December 7, 2022 · Updated October 19, 2026

The 4Cs of diamonds are cut, color, clarity and carat weight, the four scales that GIA built between the 1940s and 2006 so that any two people anywhere could describe the same diamond the same way. Cut is graded from Excellent (or Ideal) down to Poor and is the one that decides how much a diamond sparkles; color runs from D, colorless, to Z, light yellow or brown; clarity runs eleven steps from Flawless to Included 3, judged under 10x magnification; and carat is weight, 200 milligrams to the carat, which only loosely predicts size. In a mined diamond every step on every scale costs money. In a lab-grown diamond three of the four have nearly stopped mattering to the price: on October 19, 2026 the least expensive 2 carat round in Clairamor's picker was $1,138, and moving it from G to D color added $207, from VS2 to VVS2 clarity $90, and from Excellent to Ideal cut nothing at all, while the step from 2 carats to 3 added $727. This page is the whole system on one screen: the grading chart for all four Cs, what each grade actually looks like on a hand, what each grade costs in lab-grown from a live inventory, how the laboratories apply the 4Cs to lab-grown stones now that GIA has stopped grading them letter by letter, and which grades are worth paying for. Each C has its own longer guide, linked from its section, and every price here is from our picker on the date given, so treat the numbers as a snapshot and the picker as the live version. Shape is the one choice the 4Cs leave out; our diamond shapes guide compares all nine shapes we set. What a whole ring costs once the grades are chosen is in our engagement ring cost guide. Our 5 carat diamond ring guide shows how the grades are priced at the top of the carat scale, where a G can read faintly warm and each grade step costs the most.

The 4Cs at a glance

What the 4Cs are, and where they came from

Before the 4Cs there was no shared language for a diamond. A jeweler in one city might call a colorless stone "first water" and a slightly tinted one "second water"; another might say a stone was "clean" or "made well" and mean something different by both; and only carat weight, in use since the 1500s and standardized at 200 milligrams in 1907, meant the same thing in two shops. In the 1940s Robert M. Shipley, the founder of the Gemological Institute of America, coined "the 4Cs of diamond quality" as a mnemonic for his students, and his successor Richard T. Liddicoat and his colleagues turned the four words into a grading system with fixed procedures: the D-to-Z color scale, introduced in 1953 and graded by comparing a stone face down against a set of master stones under controlled light, the Flawless-to-Included clarity scale, graded at 10x magnification, and, after fifteen years of modeling and more than 70,000 observations of real stones, a cut grade for round brilliants, introduced in January 2006. Those scales are what every laboratory in the world now uses, with small differences in vocabulary: IGI puts Ideal above Excellent on its cut scale, and the American Gem Society, whose laboratory became part of GIA at the end of 2022, grades cut from 0 to 10 with 0 called Ideal.

The four words are also the order in which most guides present them, and the reverse of the order in which they matter to the price of a lab-grown diamond. In a mined stone every grade is a scarcity: a D is rarer than a G, a Flawless rarer than a VS2, a well-cut stone wastes more rough than a deep one, and a 2 carat crystal is far rarer than two 1 carat crystals, so every step on every scale is paid for. A grower makes colorless, clean crystals on purpose, cuts them to the best proportions because there is no reason not to, and grows a bigger one by leaving it in the chamber longer, so in lab-grown the top color, clarity and cut grades are the ordinary stock and only weight still carries a real price. Our lab-grown vs natural guide explains how the two kinds of diamond form; this page is about how both are graded and what the grades are worth.

The diamond grading chart: all four scales on one page

Read each row from best to least. The last column is what Clairamor's picker stocks, which is the top of each scale: every stone is D to G, IF to VS2 and Ideal to Very Good, so the grades below those limits do not appear in our prices at all.

Two things the chart cannot show. First, the scales are not evenly spaced in what you can see: the gap between an Excellent and a Good cut is visible across a table, the gap between a D and an F color is invisible to a trained grader without master stones, and the gap between a VVS1 and a VS1 clarity is invisible to anyone without a microscope. Second, the scales are not evenly spaced in what they cost, and in lab-grown they have almost flattened: the sections below put a price on every step from a live inventory.

Cut: the C that makes a diamond sparkle

Cut is the most misunderstood of the four because the word has two meanings. A diamond's shape, round, oval, emerald cut, is often called its cut; the cut grade is something else, a judgment of how well the stone was fashioned from its rough, and it is the only one of the 4Cs that people, rather than nature or a growth chamber, control completely. GIA grades standard round brilliants on five steps from Excellent to Poor by weighing seven things: brightness, fire and scintillation, which are what you see; weight ratio and durability, which are whether the cutter kept hidden weight or left a thin girdle; and polish and symmetry, the craftsmanship of the facets. IGI, which reports nearly every stone in our picker, uses the same ideas and adds Ideal above Excellent. A well-cut round returns light from almost its whole face; a deep one leaks light through the pavilion and looks smaller than its weight; a shallow one looks glassy and shows a dark ring. The difference between Excellent and Good is visible from across a table, which is why cut is the C to insist on before any other. Ovals, cushions, emerald cuts and the other fancy shapes carry no cut grade on a GIA or IGI report, only polish and symmetry, so on those shapes the length-to-width ratio, the depth and the video do the grade's job; our diamond cut grade guide lines up the GIA, IGI and AGS scales, explains the proportions behind the grade, and shows how a diamond is cut from rough to polished.

In lab-grown the top grade is the ordinary stock. Of the 8,816 rounds between 1 and 3 carats in our picker on October 19, 2026, 25 percent were Ideal, 70 percent Excellent and 5 percent Very Good, and nothing below Very Good is listed at all. The price follows: the table gives the least expensive round at each grade and weight that day, D to G color and IF to VS2 clarity, with the finished price in our $950 solitaire in 14k gold.

Read the table and the mined-diamond rule reverses: the Ideal was the cheapest 2 carat round in the picker that day, because the stones that happen to be cheapest are the stones that happen to be plentiful, and Ideal and Excellent are what the growers' cutters make. The one cut decision that still costs money in lab-grown is hidden in the carat row: two rounds of the same weight can differ by two tenths of a millimeter across, and the picker lists every stone's measurements so you can buy the wider one.

Color: D to Z

The color scale starts at D rather than A because GIA wanted a clean break from the older systems, which had used A, B and C, or "first water" and "second water", to mean whatever the seller liked. D, E and F are colorless; G, H, I and J are near colorless, with a trace of warmth that shows only against a whiter stone or in a white gold setting; K to M carry a faint tint you can see; and the scale runs on to Z, below which a stone is graded as a fancy color instead. Graders judge color with the stone face down on white, next to master stones, because face up a well-cut diamond's sparkle hides tint, and that is the point most buyers miss: the grade describes a difference that is real in the laboratory and invisible on a finger. Nobody, including a jeweler, can separate a D from an F in a ring, and in yellow or rose gold a G reads as white as a D. Our diamond color scale guide shows each grade, what you can see, which metal flatters which letter, and what each grade costs.

Lab-grown diamonds are grown colorless on purpose, so the scale's top is where the supply is. Of the 8,816 rounds between 1 and 3 carats in our picker on October 19, 2026, 5,748 were D, 2,226 E, 760 F and 82 G, and we list nothing below G. The table gives the least expensive round at each letter and weight that day, IF to VS2 clarity and Ideal to Very Good cut.

The prices wander rather than step down, E and F costing more than D at 1 carat, because what a lab-grown stone costs depends far more on its weight and its measurements than on its letter, and the day's cheapest stone at a given letter is whichever one happens to be listed. The whole span from G to D was $16 at 1 carat and $207 at 2; in a mined diamond the same span is thousands.

Clarity: Flawless to Included

Clarity grades the inclusions inside a diamond, crystals, feathers, clouds and pinpoints, and the blemishes on its surface, by their size, number, position, color and visibility under 10x magnification. Flawless and Internally Flawless have nothing a grader can find at 10x; VVS1 and VVS2 have inclusions so small that even the grader struggles to locate them; VS1 and VS2 have minor inclusions a grader finds with effort; SI1 and SI2 have inclusions that are easy to find under the loupe and, in SI2, sometimes visible to the naked eye; and I1 to I3 have inclusions obvious to the eye that may affect brilliance or durability. The grade that matters to a buyer is not on the chart: "eye-clean," a stone with nothing visible from the ordinary distance you hold your hand, and in a round, oval, pear, cushion or radiant, whose facets scatter light and hide what is inside, VS2 and above are eye-clean essentially always. The emerald cut and the other step cuts are the exception, their long open facets working as windows, which is why a VS1 is the safer floor for them. Our diamond clarity chart shows all eleven grades, what each looks like by shape and size, and how to read the clarity plot on a report; the VS1 vs VS2 guide settles the grade most people end up choosing between.

Lab-grown crystals are grown clean, and the grading reflects it: of the 8,816 rounds between 1 and 3 carats in our picker on October 19, 2026, 1,068 were Internally Flawless, 2,433 VVS1, 2,861 VVS2, 2,010 VS1 and 439 VS2, and we list nothing below VS2. The table gives the least expensive round at each grade and weight that day, D to G color and Ideal to Very Good cut.

The ladder costs $133 from VS2 to IF at 1 carat and $1,090 at 2, and almost all of the second figure sits on the last rung: VS2 to VVS1 spanned $302 at 2 carats and IF then added $788 more, for a difference between "nothing visible at 10x except from the back" and "nothing visible at 10x" that no one will ever see on a hand. The clarity grade to buy in lab-grown is the lowest one we list, VS2, in any brilliant shape, and VS1 in an emerald cut, with the saving spent on weight.

Carat: weight, not size

A carat is a unit of weight, 200 milligrams, divided into 100 points, so a 0.75 carat stone is a "seventy-five pointer"; the word comes from the carob seed, which traders once used as a counterweight, and the metric carat replaced the regional versions in 1907. Weight is the easiest of the 4Cs to state and the easiest to misread, because people hear it as size. Size is the stone's face-up measurement in millimeters, and only a well-cut round converts reliably from one to the other: about 6.4 mm at 1 carat, 7.3 mm at 1.5, 8.1 mm at 2, 9.3 mm at 3, 10.2 mm at 4 and 11 mm at 5. A deeper stone of the same weight is smaller across because its weight sits below the girdle where it cannot be seen, and a longer shape of the same weight covers more finger than a round, which is why an oval or a marquise looks larger carat for carat. Our diamond carat size chart gives every weight in millimeters, on the hand and by shape, and our 3 carat guide covers the size at which the ring starts to change how it wears.

Carat is the one C that still moves a lab-grown price, and the curve is gentler than in mined diamonds, where the price per carat climbs with every weight because large rough is rare. A grower makes a bigger crystal by leaving it in the chamber longer, so the price rises roughly with the weight rather than leaping at each carat. The table gives the least expensive round at each weight in our picker on October 19, 2026, D to G color, IF to VS2 clarity and Ideal to Very Good cut, with what it makes in our $950 solitaire, beside StoneAlgo's average for a natural diamond of the same weight the same week.

Two habits from the mined-diamond era survive in a faint form. Buying just under a round number still saves a little, a 2.92 carat round costing $1,514 that day against $1,865 for a 3.05, for two tenths of a millimeter; and the setting, which does not change with the stone, is now the larger part of a 1 carat ring and the steadier part of any ring, so choose it first. The lab-grown diamond price guide prices every weight, shape and grade from the same picker and explains where the prices are heading.

Which of the 4Cs matters most?

Cut, then carat, then the other two, and the order comes from what each one does on a hand rather than from what each one costs. Cut is the only C you can see from across a room: a well-cut round throws light back at you in a way a deep or shallow one cannot, and no color or clarity grade can rescue a poorly cut stone. Carat is the second thing anyone notices, and in lab-grown it is also where the money goes, so the budget decision is almost entirely a weight decision. Color and clarity come last because, inside the ranges a good lab-grown inventory stocks, they are not visible: no one separates a D from an F in a ring, and no one finds a VVS2 inclusion without a microscope. In mined diamonds the advice is subtler, because a buyer has to trade color and clarity against weight to afford the stone at all, and the classic mined-diamond compromise, an H or I color and an SI1 clarity to buy a bigger stone, is the right call there. In lab-grown the compromise has disappeared with the premium: on October 19, 2026 the widest spread on any of the three ladders in a 2 carat round in our picker was $302, from VS2 to VVS1, before the Internally Flawless outlier, against $727 for the step from 2 carats to 3.

A worked example makes the order concrete. With $2,500 for the whole ring and our $950 solitaire in 14k gold, that day's picker offered a 2 carat G VS2 Ideal round at $1,138, which left $412; a 2 carat D VS1 at $1,345, the same ring to the eye with $205 left; a 2.5 carat G VS1 Excellent at $1,422 for $128 under budget; or, for $2,228, a 2 carat Internally Flawless that would have put the ring $678 over the budget and looked identical to the $1,138 stone. The grades at the top of the color and clarity scales are real, and a report will always confirm them, but the person wearing the ring sees the cut and the millimeters, and the 2.5 carat is the one people notice. Our price calculator prices any stone in the picker with any setting on the day you use it.

Do the 4Cs apply to lab-grown diamonds?

Yes, and with one important change in who applies them. A lab-grown diamond is carbon in the same crystal structure as a mined one, with the same hardness and the same refractive index, so it is cut with the same tools, graded with the same instruments and described on the same four scales; a laboratory tells the two apart only with instruments that read the crystal's growth pattern and trace elements, and the report says which it is. IGI has graded lab-grown diamonds on the full 4Cs since 2005 and reports nearly every stone in our picker; HRD Antwerp grades them the same way and is more common in Europe. GIA, which wrote the scales, is the exception. On June 2, 2025 it announced that it would stop describing lab-grown stones with the D-to-Z and Flawless-to-Included scales, on the grounds that more than 95 percent of them land in a narrow band at the top of both, and its replacement, the Laboratory-Grown Diamond Quality Assessment, launched on October 1, 2025. The assessment still examines color, clarity, cut, polish and symmetry, but it reports one of two words: Premium for a stone that is D color, VVS2 or better and Excellent in cut, polish and symmetry all at once, and Standard for any stone that clears the lower thresholds, J color, VS2 clarity and Very Good cut, polish and symmetry, without meeting every Premium one; below that no assessment is issued. So a GIA-assessed lab-grown stone bought today tells you which band it sits in, not which letter, while an IGI or HRD report, or a GIA report issued before the change, still gives the grades. Our diamond certification guide compares the three laboratories line by line and shows how to verify a report in under a minute.

The reason GIA gave is the same fact that runs through this page. The 4Cs were built to sort a natural population in which most stones are tinted and included and a few are not. A grown population is the reverse: of the 8,816 rounds between 1 and 3 carats in our picker on October 19, 2026, 90 percent were D or E, 72 percent were VVS2 or better, and 95 percent were Ideal or Excellent cut, under a filter that admits nothing below G, VS2 or Very Good in the first place. On such a population the scales still describe each stone exactly; what they no longer do is separate stones by price. That is the whole case for buying a lab-grown diamond by its cut and its millimeters and letting the report confirm the rest.

How to read the 4Cs on a report and in our picker

A laboratory report states the 4Cs on four lines, and a lab-grown report adds two more that a mined report does not carry. Shape and cutting style come first, then measurements in millimeters, then carat weight, color grade, clarity grade and, on a round, the cut grade, with polish and symmetry below it and fluorescence after that. A lab-grown report also names the growth method, HPHT or CVD, and any post-growth treatment, and it carries the report number that is inscribed on the stone's girdle. The proportions diagram gives the depth and table percentages and the crown and pavilion angles, which are what the cut grade summarizes; the clarity plot maps the inclusions the grader found, which is how you check that a VS2's inclusion sits where the prongs or the facets will hide it. Every report can be checked against the laboratory's own database by its number, and the inscription can be read under a loupe against the report before the stone is set.

Our picker shows the same lines for every stone, with the filters set to the top of each scale: D to G color, IF to VS2 clarity, Ideal to Very Good cut, and an IGI, GIA or HRD report linked from the listing beside a 360 video. The filters mean you cannot choose a grade we would not set, so the useful way to read the picker is by the columns the grades do not cover. Sort a weight band by price, read the measurements column and take the widest stone; check the depth and table against the cut grade guide's ranges, 59 to 63 percent and 54 to 60 for a round; watch the video for the bow-tie on an oval or a marquise and for the windowing of an emerald cut; and open the report to see the plot and the inscription number. If a report is not showing on a listing, ask us and we will send it. The grades are a floor; the measurements and the video are how you choose between stones that all clear it.

Which grades should you buy?

For a lab-grown diamond the answer is short, and it is the opposite of the mined-diamond answer in every C but one. Cut: Ideal or Excellent on a round, with Excellent polish and symmetry, and on a fancy shape Excellent polish and symmetry with the ratio from its shape guide, because the top grade costs nothing extra and is the one difference you will see. Color: anything from D to G, chosen by the metal rather than the letter, a D or E if the ring is white gold or platinum and the whiteness matters to you, a G in yellow or rose gold where the metal warms every stone the same; the difference in price is tens of dollars at 1 carat and about $200 at 2. Clarity: VS2 in a round, oval, pear, cushion, radiant or marquise, VS1 in an emerald cut, and nothing higher unless the price is the same that day, which it sometimes is. Carat: as much as the budget allows after the setting, bought by the millimeter rather than the point, with a look at the band just under a round number. On October 19, 2026 that recipe produced a 2 carat G VS2 Ideal round for $1,138 and a 3 carat F VVS2 Excellent for $1,865; the same recipe in mined diamonds, had it been affordable, would have put the money in the opposite order.

Where Clairamor fits

Every diamond in Clairamor's picker is lab-grown and sits at the top of all four scales by design: D to G in color, IF to VS2 in clarity, Ideal to Very Good in cut, from about a quarter of a carat to 15 carats across the eight shapes we set, each listed with its measurements, its IGI, GIA or HRD report and a video. On October 19, 2026 that was 50,836 stones of 1 carat and up, 9,528 of them rounds, with 5,528 stones of 1 carat and up under $1,000. Every setting is priced without the center stone, from $950 for the 14k solitaire, so the ring's price is the setting you choose plus the stone you choose, and the price calculator adds them up on the day. We check the inscription against the report before a stone is set, and every ring ships with the report and an insurance appraisal. Take the finished ring off for the gym, the garden and any work with tools or ropes, and have the prongs checked when it is cleaned.

Torn between a D and a G, or between a VS1 and a bigger VS2? Book a design consultation.

Frequently asked questions

What are the 4Cs of diamonds?

Cut, color, clarity and carat weight, the four scales GIA developed between the 1940s and 2006 to describe a diamond's quality. Cut grades how well a round was fashioned, from Excellent (Ideal on IGI and AGS reports) to Poor; color runs from D, colorless, to Z; clarity runs eleven steps from Flawless to I3 at 10x magnification; and carat is weight, 200 milligrams to the carat.

Which of the 4Cs is most important?

Cut, because it is the only grade visible from across a room: a well-cut round returns light that a deep or shallow one leaks. Carat comes second, and in lab-grown it is where the money goes. Color and clarity come last: inside D to G and IF to VS2 the differences are invisible on a hand, and on October 19, 2026 they moved a 2 carat round $302 at most.

What is the 4Cs diamond chart?

A single table of all four scales. Cut: Excellent or Ideal, Very Good, Good, Fair, Poor. Color: D to F colorless, G to J near colorless, K to M faint, N to Z tinted. Clarity: FL, IF, VVS1, VVS2, VS1, VS2, SI1, SI2, I1, I2, I3. Carat: weight, a round running about 6.4 mm at 1 carat and 8.1 mm at 2. The chart on this page adds prices.

Do the 4Cs apply to lab-grown diamonds?

Yes. A lab-grown diamond is cut with the same tools, graded with the same instruments and described on the same four scales as a mined one, and IGI and HRD issue full 4Cs reports on them. GIA is the exception: since October 1, 2025 it assesses lab-grown stones as Premium or Standard instead, because more than 95 percent land at the top of the color and clarity scales.

What is a good diamond color and clarity?

For a lab-grown diamond, D to G color and VS2 clarity or better, which is the range Clairamor stocks: every stone in it is colorless or near colorless and clean to the naked eye in a brilliant cut, with VS1 the safer floor in an emerald cut. In mined diamonds the classic value grades are H to I color and SI1 clarity, a compromise that lab-grown prices have made unnecessary.

Is cut more important than color?

Yes, by a wide margin. The gap between an Excellent and a Good cut shows across a table, while the gap between a D and an F color is invisible without master stones, and in yellow or rose gold a G reads as white as a D. In lab-grown the top cut grade costs nothing: on October 19, 2026 the cheapest 2 carat round in Clairamor's picker was an Ideal.

What do the 4Cs cost in a lab-grown diamond?

On October 19, 2026 the least expensive 2 carat round in Clairamor's picker was $1,138, a G VS2 Ideal. Moving it to D color added $207, to VVS2 clarity $90, to VVS1 $302 and to Internally Flawless $1,090, and the Ideal cut was the cheapest grade. Weight was the real cost: a 1 carat round started at $640, a 3 carat at $1,865 and a 5 carat at $2,711.

What is the difference between carat and size?

Carat is weight, 200 milligrams, and size is the stone's measurement in millimeters. Only a well-cut round converts reliably from one to the other, about 6.4 mm at 1 carat, 8.1 mm at 2 and 9.3 mm at 3. A deeper stone of the same weight looks smaller because its weight sits below the girdle, and an oval or a marquise covers more finger than a round.

Is a D color diamond worth it?

In lab-grown, often yes, because it costs little: on October 19, 2026 a 1 carat D round in Clairamor's picker was $640, the cheapest letter that day, and a 2 carat D cost $207 more than a G. In a mined diamond a D carries a large premium for whiteness no one sees face up. Choose a D or E for white metals, a G for yellow or rose gold.

What clarity grade should I buy?

VS2 in a round, oval, pear, cushion, radiant or marquise, where the facets hide a minor inclusion completely, and VS1 in an emerald cut, whose open facets act as windows. Anything higher is invisible on a hand: on October 19, 2026 VVS2 cost $90 more than VS2 in a 2 carat lab-grown round, VVS1 $302 more and Internally Flawless $1,090 more, for differences that need a microscope.

Which laboratory grades the 4Cs on lab-grown diamonds?

IGI, which has graded lab-grown diamonds on the full 4Cs since 2005 and reports nearly every stone in Clairamor's picker, and HRD Antwerp, which is more common in Europe. GIA issued full reports until September 30, 2025 and now issues a Laboratory-Grown Diamond Quality Assessment that reports Premium or Standard instead of grades. Every report can be verified by its number on the laboratory's website.

How do I check the 4Cs on a diamond report?

Read the four lines, carat weight, color grade, clarity grade and, on a round, cut grade, then the measurements, polish and symmetry, and on a lab-grown report the growth method and any treatment. Check the report number on the laboratory's website, match it to the girdle inscription under a loupe, and use the clarity plot to see where a VS inclusion sits. Clairamor links every report.

Related reading

• Diamond cut grade chart: Ideal vs Excellent vs Very Good, what each costs and how a diamond is cut
• Diamond color scale: D to Z chart, what you can see and what each grade costs
• Diamond clarity chart: all 11 grades from Flawless to I3, what you can see and what each costs
• Diamond carat size chart: 0.5 to 5 carats in millimeters, on the hand and in lab-grown prices
• VS1 vs VS2 diamond clarity: what VS means, what you can see and what it costs
• VVS1 diamond clarity: meaning, VVS1 vs VS1, and is it worth it?
• SI diamonds: what slightly included means and whether they're worth buying
• How big is a 3 carat diamond? Size on the hand, price and why not bigger
• Lab-grown diamond prices in 2026: what a lab-grown diamond costs by carat, shape, color, clarity and cut
• Lab-grown vs natural diamonds: what is the same, what is different and what each costs in 2026
• Diamond certification companies: GIA vs IGI vs HRD, and how to read a report
• Round brilliant engagement rings: cut grade, sizes, settings and prices
• Types of engagement ring settings, explained, with prices
• Diamond size comparison simulator
• Diamond price calculator
• Diamond shapes and cuts: all nine shapes compared, with sizes, sparkle, prices and who each suits
• How much does an engagement ring cost in 2026? The average, how much to spend and what a lab-grown ring costs
• 5 carat diamond ring: how big it is on the hand, what it costs lab-grown and natural, and whether it is too big