Diamond Certificates

A diamond certificate acts as a passport for the diamond. This authenticating document is issued and printed by an independent laboratory. The certificate informs buyers whether or not the diamond is natural and lists its key attributes and qualities.

There are five primary diamond laboratories. Only two of the labs listed below have an excellent reputation when it comes to the grading of diamonds. GIA and AGS are world-renowned and the most respected diamond laboratories. GIA actually invented the current diamond grading system we use today, and are therefore the benchmarking authority in diamond grading. AGS are usually known for grading higher quality diamonds with ideal cuts and proportions; these diamonds are generally more expensive.

The Main Diamond Laboratories

• GIA is the Gemmological Institute of America (The Best Certificate)
• AGS or AGSL is the American Gemmological Society
• HRD is the Diamond High Council and represents the Belgian diamond industry
• IGI is the International Gemmological Institute
• EGL is the European Gemmological Institute

There are many other diamond certification companies throughout the world, however they do not carry a great deal of authority and as such, should be treated with caution.

GIA and AGS Diamond Certificates

You may think that as long as a diamond has a certificate, you can buy with absolute confidence. But when buying diamonds online we would strongly recommend that you only purchase diamonds with GIA or AGS certificates as these are the only two certificates that actually provide strict and accurate diamond grading.

Other, less respected, diamond certificates often assess a diamond as being anything from one to three colours or clarity grades higher, than a GIA or AGS certificate. This is why other websites may, on the face of it, seem to offer comparable diamonds at a better price (up to 10% cheaper), but in reality you won’t be comparing like with like.

For example, if a G colour diamond graded from the GIA was graded at EGL it could be graded as an E colour. So if you were to compare the price of an EGL E colour and a GIA E colour the price could be as much as 20% more, but it will not look the same. It would be cheaper to buy the GIA G colour than the EGL E colour and both would appear the same, so if you were to actually compare like for like in that case the GIA diamond would be better priced.

Now just because the grades may be lower in the diamond, this does be no means mean that the diamond will lack life; it only means you won’t actually be getting what you think you are paying for.

To illustrate how much price affects quality, a 1ct round diamond can start from £2,500 and can be as expensive as £20,000. They would both weigh the same; however the diamond colour and diamond clarity would be different. That's why we recommend trusting only GIA and AGS, especially when buying via the internet.