A diamond report, often called a certificate, is an independent laboratory’s description of a stone. It does not set a price, but it is the only reliable way to know exactly what you are buying. The two laboratories you will see most often in India are IGI and GIA.
The lines that matter most
- Report number. Unique to the stone. You can look it up on the laboratory’s own website, and it is usually laser-inscribed on the stone’s girdle.
- Origin. States whether the diamond is natural or laboratory-grown. This should never be left to assumption.
- Shape and measurements. The outline of the stone and its dimensions in millimetres. Two stones of the same carat weight can look quite different in size depending on how they are cut.
- Carat weight. The weight of the stone, not its size. One carat is 0.2 grams.
- Colour. Graded on a scale from D, completely colourless, downwards. The difference between neighbouring grades is very hard to see once a stone is set.
- Clarity. How many internal features the stone has and how visible they are, from flawless to included.
- Cut, polish and symmetry. How well the stone is proportioned and finished. These decide how much it sparkles, and they matter more than most buyers expect.
- Fluorescence. How the stone reacts to ultraviolet light. Usually of little practical importance, but worth knowing.
How to check it is genuine
Enter the report number on the laboratory’s website and make sure the details match your paper report exactly: the weight, the measurements and the grades. Our certificate check page takes you straight to the right place for IGI and GIA reports. If you would like, we can also show you the inscription on the stone under magnification.
What a report does not tell you
A report cannot tell you how a stone looks in real life, how it suits a design or whether the price is fair. Two stones with identical grades can still differ in how lively they look. That is why we always recommend seeing the stone, in person or on a video call, before it is set.