The short answer: a lab grown diamond report should state that the stone is laboratory grown, give its shape, carat weight, colour, clarity and cut where graded, mention any treatment, and carry a report number you can verify with the lab. If a report does not show these, ask why.
A grading report is the independent description of a stone. It lets you compare diamonds fairly and check what you are buying. For a lab grown diamond, the report has a few extra points that matter, especially origin.
What the report should show
| Item | Why it matters |
|---|---|
| Origin statement | It should say laboratory grown, so there is no doubt. |
| Report number | You can check it on the lab's website. |
| Shape and measurements | Confirms what the stone is and how large it looks. |
| Carat weight | The weight of the stone. |
| Colour grade | How white the stone is. |
| Clarity grade | How clean the stone is. |
| Cut grade | Given for many round stones, and shapes vary between labs. |
| Growth process and treatment | Many reports mention the method and any post growth treatment. |
Laser inscription
Many lab grown diamonds carry a tiny laser inscription on the edge, which can show the report number and the words laboratory grown. We can show you this under magnification.
Growth methods in plain words
Lab grown diamonds are made by one of two main methods. One uses very high pressure and temperature, and the other grows the crystal from a carbon rich gas. A report may name the method, and some stones have a treatment after growth to improve colour. None of this makes the stone less of a diamond, but it should be stated, and we explain what it means for the stone you are considering. See HPHT and CVD lab grown diamonds and colour treated lab grown diamonds.
Proportions and finish
Beyond the main grades, a good report lists proportions such as table size, depth and angles, and grades polish and symmetry. These numbers explain why two stones with the same grades can look different. A stone that is cut too deep can look smaller than its weight suggests, and one cut too shallow can lose brightness. We look at these details with you, not just the headline grades.
Checking a report
- Find the report number on the document.
- Look it up on the issuing lab's website.
- Check that the details match the stone and the listing.
Things to question
- A report with no origin statement.
- A report from an unfamiliar lab with no way to verify it.
- Grades that look unusually generous for the price.
Digital and printed reports
Some laboratories issue reports online only, and others offer a printed card or document. Both are valid as long as the report can be checked on the laboratory's website. Save a copy of the digital report with your other paperwork, so you can find it easily for insurance or if you ever sell or remake the ring.
Our approach
We check the report with you, and we explain each line in plain words. We also look at the stone itself, because a report describes a diamond but does not replace seeing it.
For a comparison of the main labs, see IGI vs GIA lab reports explained, and browse lab grown colourless diamonds. 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.
Frequently asked questions
Do all lab grown diamonds have reports? Not all do, which is why we recommend choosing a stone with an independent report.
Can I verify a report myself? Yes, using the number on the lab's website.
Is a cut grade given for every shape? Not for every shape, and practices vary between labs.
Is a digital report as good as a printed one? Yes, if it can be checked on the lab's website.
What if the inscription and the report do not match? Stop and ask us before you go ahead.