Diamond guide
What the grades mean
Colour, clarity, cut and carat, and the difference between natural and lab-grown, in plain words.
Grades
The four grades
Each diamond's report lists all four.
| Grade | Scale | What we suggest |
|---|---|---|
| Colour | D (colourless) to Z (tinted) | G or H looks white in a ring |
| Clarity | FL to I3 | VS2 or better looks clean to the eye |
| Cut | Excellent to Poor | Excellent or Very Good for rounds |
| Carat | Weight: 1ct is 0.2g | Shape changes how big it looks |
Natural or lab-grown
Two kinds of diamond
Both are diamond. We name which is which on every tag and report.
| Question | Natural | Lab-grown |
|---|---|---|
| Where from | Mined from the earth | Grown in a laboratory |
| Looks | The same to the eye | The same to the eye |
| Price | Higher for the same grade | Lower for the same grade |
| Resale | We make no promise | We make no promise |
We do not sell diamonds as an investment.
A report
What a grading report shows
Every centre diamond over 0.30ct comes with one.
- Origin
- Natural or laboratory grown
- Shape and cut
- Round brilliant, Excellent
- Carat
- To two decimal places
- Colour
- D to Z
- Clarity
- FL to I3
- Number
- Laser inscribed on the girdle
Diamond questions
Can you tell lab-grown from natural by eye?
No. A laboratory can, and the report says which.
Why are coloured stones heated?
Heating is a common, permanent treatment that improves colour. We always say when a stone has been treated.
Is a bigger carat always better?
Cut matters more for sparkle. A well-cut 0.90ct can outshine a poorly cut 1.00ct.