Las 4 C del diamante

The 4Cs are cut, color, clarity and carat weight — the four measurements every diamond is graded on. They are not equally important. Cut decides how a diamond looks; the other three mostly decide what it costs. If you take one thing from this page, take that.

Below is what each grade actually means, and the point on each scale where paying more stops buying you anything you can see.

Cut — the one that matters most

Cut is not the shape. Shape is round, oval, emerald. Cut is the quality of the faceting: the angles, the proportions, the polish and the symmetry. It is the only C that is entirely the work of a human being, and it is the one that determines whether light entering the stone bounces back to your eye or leaks out of the bottom.

Two diamonds with identical color, clarity and carat can look nothing alike if one is cut well and the other is not. A shallow stone looks glassy and dead in the center. A deep one looks small for its weight and goes dark. Get this right and you can be relaxed about almost everything else.

Cut grades, round brilliant
Grade What you see
Excellent / Ideal Maximum brilliance and fire. Worth the premium.
Very Good Very close to Excellent, often at a real saving.
Good Noticeably less lively. Visible side by side.
Fair / Poor Dull or dark. Avoid at any price.

Note that only round brilliants receive a full cut grade from the laboratories. Ovals, pears, emeralds and other fancy shapes are graded on polish and symmetry alone, so with those you judge with your eyes — look for even brightness across the whole stone and no dark bowtie across the middle.

Our stones are cut to Excellent or Very Good. We do not stock anything below that.

Color — how little of it there is

Diamond color is graded on absence. D is completely colorless and the scale runs down to Z, where a faint yellow or brown is obvious. Almost all of that range is invisible to a normal person looking at a ring on a hand.

Color grades
Range Grades What you see
Colorless D, E, F No color at all. Commands the highest price.
Near-colorless G, H, I, J Face-up white to the naked eye. The value range.
Faint K, L, M A warmth begins to show, especially in larger stones.
Noticeable N to Z Visible yellow or brown tint.

Two things change the calculus. Metal: a G or H set in yellow or rose gold reads as white, because the eye compares the stone to the band. Size: color is easier to see in a 3-carat stone than a 1-carat one, so go a grade higher as you go larger.

Our diamonds are near-colorless — the range where a stone looks white without paying for a laboratory distinction nobody will ever notice.

Clarity — what is inside

Every diamond forms with tiny internal features: crystals, feathers, clouds. Clarity grades how many, how large and how visible they are under 10x magnification. The phrase to hold on to is eye-clean — a stone with no inclusion visible to the unaided eye at normal viewing distance.

Clarity grades
Grade Meaning Eye-clean?
FL / IF Flawless / Internally Flawless Yes — and you pay heavily for it
VVS1 / VVS2 Very very slightly included Yes
VS1 / VS2 Very slightly included Yes — the sweet spot
SI1 / SI2 Slightly included Usually, but check the stone
I1 / I2 / I3 Included No — visible without magnification

Above VS1 you are buying a certificate, not an appearance. Our stones are VS1 to VS2 for exactly that reason.

Carat — weight, not size

A carat is 0.2 grams. It measures weight, and weight is not the same as how big a stone looks. Two things follow from that.

First, price steps up sharply at whole and half-carat marks, because those are the numbers people ask for. A 1.90-carat stone costs meaningfully less than a 2.00-carat stone and the difference in diameter is under half a millimeter. Nobody has ever noticed.

Second, shape changes how large a given weight looks. Elongated cuts — oval, marquise, pear, emerald — spread more of their weight across the face of the stone, so they read larger than a round of the same carat. A well-cut round also looks larger than a deep one, because less of its weight is buried below the girdle.

How to spend a fixed budget across the four

  • Cut first, always. Excellent or Very Good, no exceptions.
  • Color: near-colorless. Go warmer in yellow or rose gold, cooler as the stone gets bigger.
  • Clarity: eye-clean. VS1 or VS2. Paying past that buys nothing visible.
  • Carat: buy just under a landmark. 1.90 rather than 2.00, 0.90 rather than 1.00.

Because lab-grown diamonds cost a fraction of mined stones of the same grade, this arithmetic is far kinder than it used to be — the same budget reaches a better cut and a larger stone at once. See how to set a budget.

Is there a fifth C?

Certification, usually. Every Diamond Domain stone is independently graded and comes with its report, plus a laser inscription on the girdle matching the stone to its certificate. Without one, a grade is just a claim.

Frequently asked questions

Which of the 4Cs is most important?

Cut. It is the only one that changes how a diamond actually looks, because it governs how light moves through the stone. Color, clarity and carat mostly govern price. A well-cut diamond of modest color and clarity will outshine a poorly cut one with better grades.

What clarity grade should I buy?

VS1 or VS2. Both are eye-clean, meaning no inclusion is visible without magnification, and they cost substantially less than VVS or Flawless grades that look identical on the hand.

What color grade should I buy?

Near-colorless, G through J, for most rings. It faces up white to the naked eye. You can go a grade warmer in yellow or rose gold, and should go a grade cooler above about 2 carats, where any tint is easier to see.

Does a bigger carat weight always mean a bigger-looking diamond?

No. Carat is weight, not size. An elongated shape such as oval or marquise looks larger than a round of the same weight because more of the stone sits face-up, and a well-cut stone looks larger than a deep one because less weight is hidden below the girdle.

Are lab-grown diamonds graded on the same 4Cs?

Yes. Lab-grown diamonds are graded by the same independent laboratories against the same cut, color, clarity and carat standards as mined diamonds, and the report states the growth method. How lab-grown diamonds are made.

What does eye-clean mean?

That no inclusion is visible to the unaided eye at normal viewing distance, roughly arm's length. It is the practical standard that matters, as opposed to the laboratory grade assigned under 10x magnification.

Where to go next

Every Diamond Domain diamond is cut to Excellent or Very Good, near-colorless, VS1–VS2, and independently certified. Free insured shipping both ways, free 30-day returns, free engraving and a lifetime warranty. Call (888) 709-7077 or book a free consultation.