The 4Cs are carat (weight), cut (how well the diamond is shaped and polished), color (how white it looks) and clarity (how many tiny marks are inside or on it). Cut matters most for sparkle, and carat matters most for size and price, so most people get the best value by putting cut first and staying flexible on color and clarity.
Every diamond is graded on these four points. You don't need to memorize the charts. You just need to know what each grade means and which differences you can actually see when the ring is on your hand.
What does carat mean?
Carat is weight, not size. One carat equals 0.2 grams. A heavier diamond is usually bigger across the top, but a deep, poorly cut stone can carry extra weight underneath where nobody sees it.
For a well-cut round diamond, these face-up sizes are typical:
| Carat weight |
Approx. diameter (round) |
| 0.25 ct |
4.1 mm |
| 0.50 ct |
5.2 mm |
| 0.75 ct |
5.8 mm |
| 1.00 ct |
6.5 mm |
| 1.50 ct |
7.4 mm |
| 2.00 ct |
8.2 mm |
On pieces with many small stones, like a pavé ring or a diamond bracelet, you will see "total carat weight" (ctw). That is all the diamonds added together, not one stone.
Why is cut the most important C?
Cut is the only C that people control. A well-cut diamond sends light back up through the top, which is what you see as sparkle and brightness. A stone cut too deep or too shallow lets light leak out the sides and looks dull, even with great color and clarity.
Cut grades usually run Excellent (or Ideal), Very Good, Good, Fair and Poor. Don't confuse cut with shape. Shape is round, princess, oval, emerald, pear and so on. Cut is how well that shape was finished.
- For a round diamond, aim for Excellent or Very Good.
- Fancy shapes (oval, pear, marquise) often don't get an official cut grade, so look at the stone in person or in clear video.
- A slightly smaller stone with a great cut can look bigger and brighter than a heavier stone with a poor one.
What do diamond color grades mean?
Color is graded on a letter scale from D (completely colorless) to Z (light yellow or brown). The differences between neighboring grades are tiny and are judged face-down under controlled light.
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D–F: colorless. The top of the scale.
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G–J: near colorless. Looks white face-up to most people.
-
K–M: faint warmth you may notice next to a whiter stone.
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N–Z: visible yellow or brown tint.
Your metal matters here. In yellow gold, a warmer diamond in the H to K range blends right in. In white gold or platinum, a G or H will look crisper.
What is diamond clarity, and can you see it?
Clarity measures inclusions (tiny crystals or feathers inside the stone) and blemishes (marks on the surface). Grades are set under 10x magnification:
| Grade |
What it means |
| FL / IF |
Flawless / internally flawless |
| VVS1 / VVS2 |
Very, very slightly included; very hard to find even at 10x |
| VS1 / VS2 |
Very slightly included; minor marks at 10x |
| SI1 / SI2 |
Slightly included; sometimes visible to the eye |
| I1 / I2 / I3 |
Included; often visible to the eye |
The phrase to know is "eye-clean." That means you can't see anything without magnification. Many VS2 and SI1 stones are eye-clean and cost far less than VVS or Flawless.
Where should you spend your budget?
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Cut first. It drives sparkle more than anything else.
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Carat next. Pick the size that looks right on your hand.
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Color by metal. Warmer is fine in yellow gold; go whiter for white gold.
-
Clarity last. Eye-clean is the goal, not perfect.
Also ask whether a stone is natural or lab-grown, because both are graded on the same 4Cs. Our guide to natural diamonds, lab-grown diamonds and CZ explains the difference. Shopping for a ring? Check your size first with our at-home ring size guide.
Every listing in our ring collection shows the metal, karat, weight and stones, and you can browse diamond studs in earrings too.
Visit or text us
Want to see the difference between grades with your own eyes? Come by our family-owned store at 260 Main St, Orange, NJ, open 7 days, or call or text (973) 673-3800. Start browsing in our rings collection.
Diamond Basics: Carat, Cut, Color and Clarity in Plain English
The 4Cs are carat (weight), cut (how well the diamond is shaped and polished), color (how white it looks) and clarity (how many tiny marks are inside or on it). Cut matters most for sparkle, and carat matters most for size and price, so most people get the best value by putting cut first and staying flexible on color and clarity.
Every diamond is graded on these four points. You don't need to memorize the charts. You just need to know what each grade means and which differences you can actually see when the ring is on your hand.
What does carat mean?
Carat is weight, not size. One carat equals 0.2 grams. A heavier diamond is usually bigger across the top, but a deep, poorly cut stone can carry extra weight underneath where nobody sees it.
For a well-cut round diamond, these face-up sizes are typical:
On pieces with many small stones, like a pavé ring or a diamond bracelet, you will see "total carat weight" (ctw). That is all the diamonds added together, not one stone.
Why is cut the most important C?
Cut is the only C that people control. A well-cut diamond sends light back up through the top, which is what you see as sparkle and brightness. A stone cut too deep or too shallow lets light leak out the sides and looks dull, even with great color and clarity.
Cut grades usually run Excellent (or Ideal), Very Good, Good, Fair and Poor. Don't confuse cut with shape. Shape is round, princess, oval, emerald, pear and so on. Cut is how well that shape was finished.
What do diamond color grades mean?
Color is graded on a letter scale from D (completely colorless) to Z (light yellow or brown). The differences between neighboring grades are tiny and are judged face-down under controlled light.
Your metal matters here. In yellow gold, a warmer diamond in the H to K range blends right in. In white gold or platinum, a G or H will look crisper.
What is diamond clarity, and can you see it?
Clarity measures inclusions (tiny crystals or feathers inside the stone) and blemishes (marks on the surface). Grades are set under 10x magnification:
The phrase to know is "eye-clean." That means you can't see anything without magnification. Many VS2 and SI1 stones are eye-clean and cost far less than VVS or Flawless.
Where should you spend your budget?
Also ask whether a stone is natural or lab-grown, because both are graded on the same 4Cs. Our guide to natural diamonds, lab-grown diamonds and CZ explains the difference. Shopping for a ring? Check your size first with our at-home ring size guide.
Every listing in our ring collection shows the metal, karat, weight and stones, and you can browse diamond studs in earrings too.
Visit or text us
Want to see the difference between grades with your own eyes? Come by our family-owned store at 260 Main St, Orange, NJ, open 7 days, or call or text (973) 673-3800. Start browsing in our rings collection.