The short answer: a diamond report lists the stone's shape, weight, measurements, colour, clarity and cut grade, with a report number that you can use to check it, and reading it in the right order lets you check a stone in a few minutes. Formats vary by laboratory.
Reports look dense at first. This cheat sheet shows what to read first and what each section tells you.
One page, step by step
| Section | What it tells you |
|---|---|
| Report number | Identifies the report and may be looked up online. |
| Shape and cutting style | Outline and facet arrangement. |
| Measurements | Size in millimetres. |
| Carat weight | Weight of the stone. |
| Colour grade | How colourless the diamond is. |
| Clarity grade | Internal and surface features. |
| Cut grade | For round diamonds, a grade of the cut quality. |
| Polish and symmetry | Finish quality. |
| Fluorescence | Glow under ultraviolet light. |
| Comments | Notes, such as treatments or the method of growth. |
Natural or lab grown
Reports state whether a stone is natural or laboratory grown. We label each stone clearly. Browse diamonds and lab grown colourless diamonds.
Check the details
- Match the report number to the stone, which may be inscribed.
- Compare the weight and measurements.
- Read the comments.
- Check the shape and the grades against what you were told.
What to read first
Start with the report number, the shape and the weight, since they confirm that the report belongs to your stone. Then read colour, clarity and cut, and finish with the comments, where useful notes sometimes sit.
A worked example
Imagine a report for an oval stone. You check that the report number matches the one we quoted, and that the shape says oval. You compare the weight and the length and width in millimetres, because the length to width ratio tells you how elongated the oval will look. Then you read the colour and clarity grades and compare them with the written quote. Finally you read the comments for anything unexpected. If any detail does not match what you were told, ask us before you approve the design.
The plot diagram
Many full reports include a small diagram of the stone with marks showing where inclusions sit, plus a key explaining what each mark is. It helps you understand the clarity grade and match the report to the stone under magnification. Shorter reports may leave the plot out. See the clarity scale explained.
Report types
Different laboratories use different formats and terms, and some grade more finely than others. Compare like with like, and if two reports use different wording, ask us how they relate. See IGI vs GIA lab reports.
A report does not show
A report does not show how the stone looks to you. Two stones with the same grades can look different, because cut and proportions affect sparkle. Look at the stone on video and judge it for yourself.
A higher grade is not automatically better value
Small differences in grade can be hard to see by eye yet affect price. Think about what you notice and where you prefer to spend. See how much should you compromise on colour and clarity.
Nothing is made until you approve the design in writing, and our standard making time is 5 to 6 weeks, which can vary with your location and how busy we are. Pieces start from £600.
See reading your invoice and certificate and the jewellery glossary.
Frequently asked questions
Does every diamond have a report? No, so ask.
Is a higher grade better value? Not necessarily.
Can I check a report online? Many laboratories offer lookups.
Can you explain my report? Yes, send us a copy.
What does fluorescence mean? It describes how a stone glows under ultraviolet light, and it is one detail to read alongside the others.