Diamond 4Cs: Cut, Colour, Clarity, Carat
The four measures every diamond is graded on — and where your money makes the most visible difference.
Reviewed by Adnan Ali, Graduate, GIA Diamond Grading · Updated 2026-10-24
Every diamond, lab-grown or natural, is described by the same four measures: cut, colour, clarity and carat weight. Together they decide how a stone looks and what it costs. Understanding them lets you put your budget where you will actually see it.
Cut
Cut is how well a diamond's facets are proportioned, angled and finished. It is what turns light entering the stone into brightness and sparkle, and it is the quality you notice first from across a room. A well-cut diamond can look livelier than a larger, poorly cut one. Cut is not the same as shape: round, oval, emerald and pear are shapes, and each can be cut well or badly.
Colour
White diamonds are graded on a scale that starts at D, completely colourless, and runs down the alphabet as a faint yellow or brown tint becomes easier to see. D to F are colourless; G to J are near-colourless, and once set in a ring most people cannot see colour in them without a colourless stone beside them for comparison. Yellow gold is more forgiving of a warmer stone than white gold or platinum.
Clarity
Clarity describes the tiny internal features (inclusions) and surface marks (blemishes) almost every diamond has. The scale runs from Flawless through Internally Flawless, VVS1 and VVS2 (very, very slightly included), VS1 and VS2 (very slightly included), SI1 and SI2 (slightly included) to I1–I3 (included). From VS downwards the differences are usually only visible under magnification; many SI stones are clean to the naked eye, but it depends on where the inclusions sit.
Carat
Carat is weight, not size: one carat is 0.2 grams, and a carat divides into 100 points, so a 0.50ct stone is '50 points'. Two diamonds of the same weight can look different sizes depending on their shape and how deep they are cut. Prices rise steeply at popular weights such as 0.50ct and 1.00ct, so a stone just under one of those marks can look almost identical for noticeably less.
Our diamond quality options
Where offered, choose from one lab-grown diamond quality option or three natural-diamond quality options. The available choices and their colour and clarity grades are shown on each product page. Engagement-ring centre diamonds are selected separately: choose from the carat, colour and clarity options shown on the design’s product page. Each design has a fixed centre-diamond shape. The table below gives examples of quality labels; it does not promise every option on every design.
| Option | Colour | Clarity | In short |
|---|---|---|---|
| Lab Diamond | E–F | VVS–VS | An example colourless option —, inclusions hard to find even under magnification |
| Natural | F–G | VS | Premium natural stones, clean to the naked eye |
| Natural | G–H | SI | The best-value natural option — minor inclusions, typically invisible without magnification |
| Natural | H–I | SI | The most affordable natural option — bright, with slight inclusions that are difficult to see with the naked eye |
Where to spend, where to save
- Prioritise cut: it has the biggest effect on how bright the stone looks.
- In a white metal, near-colourless is enough for most people; in yellow gold you can go a little warmer.
- Eye-clean matters more than a top clarity grade that only shows under a loupe.
- Choose carat weight last, once the other three look right for your budget.
See the qualities side by side
All diamond studs →
Does the centre-diamond carat weight include the accent diamonds?
No. For engagement rings, the centre-diamond weight and the accent-diamond weight are stated separately. The selected centre-diamond weight does not include the accent diamonds.
Is the stated diamond carat weight for one earring or the pair?
The stated diamond carat weight is the total for the pair of earrings.