Lab-Grown Diamond Guide
Diamond Quality Rankings and Quality Chart
Understand diamond quality with charts for colour, clarity, cut, polish and symmetry, and practical advice on balancing appearance and budget.
When discussing diamond quality rankings, many people look only at the letters for colour or clarity. A diamond's appearance, however, is a combination of the 4Cs: cut, colour, clarity and carat weight. Its millimetre dimensions, polish, symmetry, fluorescence and actual light performance should also be assessed.
Brief Diamond Quality Chart
| Component | General Order from Higher to Lower | Visible Effect |
|---|---|---|
| Colour | D, E, F, G, H, I, J... | How colourless or warm the stone looks |
| Clarity | FL, IF, VVS1, VVS2, VS1, VS2, SI1, SI2, I... | Visibility of internal and external characteristics |
| Cut | Excellent, Very Good, Good... | Brilliance, fire and light return |
| Polish | Excellent, Very Good, Good... | Finish of the facet surfaces |
| Symmetry | Excellent, Very Good, Good... | Geometric alignment of the facets |
1. Cut Quality
Cut determines how a diamond handles light. The cut grade is particularly important for round brilliant stones. A well-cut stone with lower colour or clarity grades can look livelier than a poorly cut stone with higher grades.
Not every report provides an overall cut grade for fancy shapes. In that case, assess proportions, symmetry, dark areas and the actual video together.
2. Colour Rankings
| Group | Grades | General Description |
|---|---|---|
| Colourless | D-F | Little or no visible colour under controlled conditions |
| Near colourless | G-J | Slight warmth; varies with the setting and viewing conditions |
| Faint colour | K-M | A warm tone may be more noticeable |
In everyday wear, nearby grades can look very similar when they are not compared side by side. Read the diamond colour guide for details.
3. Clarity Rankings
| Grade | Meaning | Practical Interpretation |
|---|---|---|
| FL-IF | Flawless or internally flawless | Very rare; the difference mainly concerns magnification |
| VVS1-VVS2 | Very, very small internal characteristics | Difficult for an experienced observer to see at 10x magnification |
| VS1-VS2 | Very small internal characteristics | Many stones may look clean to the naked eye |
| SI1-SI2 | Small internal characteristics | May be visible depending on location and stone size |
| I group | Noticeable internal characteristics | Appearance or durability may be affected |
You can find grade details in diamond clarity grades.
4. Carat Is Not Quality
Carat expresses weight. A large stone is not automatically higher quality. Stones with the same carat weight may have different millimetre dimensions, cuts, colours and clarity grades.
How to Choose the Most Sensible Quality
- First decide on the shape and target millimetre dimensions.
- Prioritise cut and light performance.
- Choose a colour range to suit the setting's colour.
- Look for eye-clean clarity.
- Verify the report and laser inscription number.
- Allocate the remaining budget to carat weight or design.
If you are deciding between options such as D-VVS and E-VS, see the comparison of sensible diamond quality choices.
General Approach According to Budget
- Visual priority: good cut, balanced millimetre dimensions and eye-clean clarity.
- Documentation priority: a verifiable report and clearly stated specifications.
- Rarity priority: higher colour and clarity grades.
- Size priority: more efficient face-up dimensions at similar colour and clarity grades.
Compare reported stones by their specifications on the certified lab-grown loose diamonds page.
Frequently Asked Questions
What is the best diamond quality?
On paper, the highest grades are D colour and FL clarity, but the best purchase depends on wear, appearance and budget.
Is VS or SI better?
VS is a higher clarity group. However, an eye-clean SI stone can offer good value depending on the location of its internal characteristics.
Is colour or clarity more important?
It depends on the stone and setting. Cut should be the first priority in most choices, while colour and clarity should be balanced according to their visible effect.