Diamond Certificates

A diamond certificate would simply be described as a passport for the diamond. This is a document printed by an independent laboratory that states whether or not the diamond is natural and lists its attributes and qualities.

There are five well know diamond labs. Only two of the labs listed below have a top 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 benchmark in diamond grading. AGS are usually known for grading higher quality diamonds with ideal cuts and proportions, these diamonds are usually more expensive.

The Main Diamond Laboratories

- GIA is the Gemological Institute of America (The Best Cert)
- AGS or AGSL is the American Gemological Society
- HRD is the Belgium Government
- IGI is the International Gemological Institute
- EGL is the European Gemological Institute (ZS Diamonds does not offer this Cert)

There are approx many other diamond certification companies around the world, but these are not known throughout the world, nor carry any respect.

GIA and AGS Diamond Certificates

You may think that as long as the diamond has a certificate then that's fine. But especially when buying on the Internet we would recommend only buying diamonds with GIA or AGS certificates. As these are the two certificates that are the most respected the world throughout, but more importantly the only two certificates that actually provide strict and accurate diamond grading.

The other diamond certificates can be anything from one to three colour or clarity grades better. This is why other websites may seem to offer a certain diamond at a 10% better price but in actual fact you won't be comparing like for like. 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.

HRD and IGI are known to be not as accurate as GIA, but not as bad as EGL, usually up to two grades difference.

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 wouldn't actually be getting what you think you are paying for.

Just to prove how much price affects quality, a 1ct round diamond can start from £2,500 and can be as expensive as £20,000. But they would weigh the same; just 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.