Two lines on a diamond certificate decide more about how a stone looks than almost anything else: its colour grade and its clarity grade. Both are measured on fixed scales the whole trade reads from, and once you understand them you can spend where the eye actually sees a difference. Below are the full colour (color) chart and clarity chart, a combined value matrix, the 4Cs on one page, and how to find each grade on a GIA or HRD report.
Diamond colour chart (D to Z)
Colour grades how little tint a diamond shows, from D (completely colourless) down to Z (a visible pale yellow or brown). Laboratories grade it face-down against master stones under controlled light, which is why neighbouring grades usually look identical once set face-up in a ring. The chart tells you where you can stop paying, and which metal suits each grade.
| Grade | Group | What the eye sees | Best metal pairing |
|---|---|---|---|
| D | Colourless | Icy white from every angle | Platinum or white gold |
| E | No tint the eye can find | Platinum or white gold | |
| F | No tint face-up or from the side | Platinum or white gold | |
| G | Near colourless | White face-up; a trace only beside a D | Any metal |
| H | White face-up in almost any setting | Any metal | |
| I | Faint warmth from the side, white face-up | White gold, or yellow gold to look whiter | |
| J | A whisper of warmth, clearer in large stones | Yellow or rose gold | |
| K | Faint | A warm tint the eye can find | Yellow or rose gold |
| L | Warmth visible face-up | Yellow gold | |
| M | Clearly warm | Yellow gold, by choice | |
| N to R | Very light | Tint obvious to any eye | Not stocked |
| S to Z | Light | Distinct yellow or brown | Not stocked |
Our honest advice: a G or H stone faces up white in most settings and costs noticeably less than a D, so spend the saving on cut. Colour shows more in larger stones and less in small ones, and warm metal hides warmth: an I or J in yellow gold looks as white as an H in platinum. Our ring metal guide covers the pairing, and our note on fluorescence explains why some I to K stones face up whiter than their letter.
Diamond clarity chart (FL to I3)
Clarity grades the tiny natural features inside a diamond (inclusions) and on its surface (blemishes), judged under 10× magnification. The grader weighs their size, number, position, type and how much they stand out. Most are invisible to the naked eye, which is the point of the term eye-clean: once nothing shows without a loupe, higher grades buy rarity on paper, not beauty on the hand.
| Grade | Meaning | Typical inclusions | Eye-clean? |
|---|---|---|---|
| FL | Flawless | Nothing inside or on the surface at 10× | Always |
| IF | Internally flawless | No inclusions; only minute surface marks | Always |
| VVS1 | Very, very slightly included | A pinpoint or faint needle, extremely hard to find at 10× | Always |
| VVS2 | Very, very slightly included | Pinpoints, a tiny feather or faint cloud, very hard to find | Always |
| VS1 | Very slightly included | Small crystals, feathers or clouds, found with effort | Virtually always |
| VS2 | Very slightly included | Minor inclusions, a little easier to find at 10× | Almost always; check step cuts |
| SI1 | Slightly included | Crystals, feathers or clouds noticeable at 10× | Often, especially under 1 carat |
| SI2 | Slightly included | Easy to see at 10×; sometimes visible to a sharp eye | Sometimes; judge each stone |
| I1 | Included | Obvious at 10×, often visible to the eye | Rarely; not stocked |
| I2 and I3 | Included | Visible to the eye; can dull brilliance or weaken the stone | No; not stocked |
Position matters as much as the letter. A white feather near the edge, hidden by a prong, beats a dark crystal under the table every time. Brilliant cuts such as round and oval hide inclusions well; step cuts such as emerald and asscher show them through their open facets. Aim for the lowest grade that is still eye-clean, often a VS2 or a well-chosen SI1.
Colour and clarity together: the value sweet spot
This is the chart most buyers actually need. It applies to round and other brilliant shapes from about half a carat to 1.5 carats, set in white gold or platinum. Find your colour on the left and read across.
| Colour | VVS2 | VS1 | VS2 | SI1 | SI2 |
|---|---|---|---|---|---|
| G | paper premium | good value | sweet spot | good value | check video |
| H | paper premium | good value | sweet spot | sweet spot | check video |
| I | paper premium | good value | good value | good value | check video |
| J | paper premium | good value | good value | check video | avoid |
- Sweet spot: faces up white and clean; the best balance of beauty and cost.
- Good value: a sound choice, with either a small premium or a small, usually invisible compromise.
- Check video: can be excellent value, but only if the actual stone proves eye-clean on its 360° video.
- Paper premium: a lovely stone, but you pay for clarity no one will see on the hand.
- Avoid: in white metal, warmth and possibly visible inclusions start to add up.
Three adjustments. For smaller stones, such as a half carat, you can move one column to the right, as inclusions and warmth are harder to see. Above 1.5 carats, or for emerald and asscher cuts, move one column to the left. In yellow or rose gold, read an I or J row as you would read H.
The full 4Cs chart: cut, colour, clarity, carat
Here is how all four Cs sit together, and where each deserves your money.
| The C | What it measures | The scale | Where the value sits |
|---|---|---|---|
| Cut | How well the stone returns light | Excellent, Very Good, Good, Fair, Poor | Excellent; a top Very Good chosen on video |
| Colour | How little tint the stone shows | D to Z | G to J, matched to the metal |
| Clarity | Inclusions and blemishes at 10× | FL, IF, VVS1 to VVS2, VS1 to VS2, SI1 to SI2, I1 to I3 | The lowest eye-clean grade, often VS2 or SI1 |
| Carat | Weight: one carat is 0.2 grams | Continuous, priced in steps | Just under round numbers, such as 0.90 or 0.45 |
GIA gives an overall cut grade only to round brilliants; fancy shapes carry polish and symmetry grades, so their light must be judged on the stone itself. Our guide to Excellent versus Very Good cut explains the difference. Carat is weight, not size, so here is what each common weight measures across the top in a well-cut round:
| Carat weight | Round diameter |
|---|---|
| 0.25 ct | about 4.1 mm |
| 0.30 ct | about 4.3 mm |
| 0.40 ct | about 4.7 to 4.8 mm |
| 0.50 ct | about 5.1 to 5.2 mm |
| 0.70 ct | about 5.7 mm |
| 0.90 ct | about 6.2 mm |
| 1.00 ct | about 6.4 to 6.5 mm |
| 1.50 ct | about 7.3 to 7.4 mm |
| 2.00 ct | about 8.1 to 8.2 mm |
| 3.00 ct | about 9.3 mm |
A stone cut deep measures less than its weight suggests, so always read the measurements line on the report. Our carat size guide shows how these sizes look on the hand, and the 4Cs explained goes deeper into each one.
How to read colour and clarity on a GIA or HRD report
On a GIA report, the grading results list the carat weight, the colour grade (printed with the American spelling, “Color Grade”), the clarity grade and, for rounds, the cut grade, followed by polish, symmetry and fluorescence. The full grading report adds a plotted diagram of the inclusions with a key to symbols, such as crystal, feather, cloud or needle. The shorter Diamond Dossier, often issued for smaller stones, gives the same grades without the plot. Read the comments line too: a note such as “clouds are not shown” means some features were left off the map, although the grade still counts them.
HRD reports use the same colour letters and the same clarity grades from VVS1 to SI2, with two naming differences: a stone with no inclusions at 10× is graded LC (loupe clean) rather than FL or IF, and the lowest grades are P1 to P3 instead of I1 to I3. Our comparison of GIA and HRD certificates covers the rest. Whichever laboratory graded the stone, verify the report number online before you pay, and check that the grades match the listing.
Common questions about the charts
What colour and clarity is the best value?
For most buyers, G or H colour with VS2 clarity, or an eye-clean SI1. The stone faces up white and clean in any setting, and the saving against a D Flawless buys a visibly better cut or a larger stone.
Is SI1 clarity good enough for an engagement ring?
Often, yes, but stone by stone. An SI1 with a small white inclusion near the edge can be perfectly eye-clean; one with a dark inclusion under the table is not. That is why we film every stone in 360° video, so you judge the actual inclusion rather than the letter.
Which colour grades look white once set?
D to H face up white in white gold or platinum for nearly every eye, and I and J usually do too in stones under about a carat. In yellow or rose gold, even K reads as white against the warm metal.
Do colour and clarity matter more than cut?
No. A well-cut stone hides a little warmth and small inclusions behind its sparkle, while a poorly cut stone shows every fault it has. Use the charts to know what you are paying for, then let cut decide between finalists.
Is the diamond quality chart different in the UK?
No. The GIA letter scales are used internationally, in the UK, Europe and here in Lebanon. Some older UK and European charts add traditional names, such as River for the top whites, but the letter grade on the report is what counts.
Choose with the chart, confirm with the video
The charts narrow the field; the stone makes the decision. Every diamond we sell is natural and certified by GIA or HRD, and we share each stone’s 360° video and certificate on WhatsApp so you can judge its colour and clarity yourself. When you are ready, browse our certified diamonds with their full grades, or message us on WhatsApp with the colour and clarity you have in mind and we will send you the stones that fit.