What diamond certification?

There is an international standard for the grading of diamonds, known as the 4 C’s, it defines the stone’s carat weight, its colour, its clarity and its cut. A certificated diamond is one that has been independently (of the retailer) graded and the carat weight, colour, clarity, cut and other factors recorded on a certificate that is sold with the diamond. There are two main types of certificate – the full certificate and the “diamond dossier”.

Is a certificated stone better than a non certificated stone?

No. All the certificate means is that someone else, independent of the seller, has assessed the stone’s characteristics.

What should I buy?

This rather depends on who you are buying from! There is little advantage in a certificate if you are buying from a respected and established retailer – in fact, you are likely to get less ‘diamond for your money’ going the certificated route as of course the price of the independent assessment has to be included in the price of the stone. You will be quite safe buying a non-certificated stone from an established jeweller based in the UK as their receipt will represent a guarantee of the stone’s grade. However, we suggest that if you are considering buying a loose diamond oversees or on the internet, a certificate might be a good idea as you may be less sure as to the credentials of the retailer.

Are certificated stones more valuable?

Contrary to popular belief, the ‘value’ of an engagement ring tends to be as much in the design and craftsmanship of the ring as in the quality of the diamond. Second-hand diamond engagement rings are plentiful in the marketplace so don’t really command a huge price, certificated or otherwise.

Does diamond certification tell you everything?

Certainly not! One H SI 0.4ct diamond will not be the same as another, even if you consider all the other criteria such as the cut etc. Every diamond is different, some have that extra sparkle factor that others just simply don’t and that is something that science just can’t define. Harriet likens it to two countryside views – one may be more beautiful than the other – you can have a go at trying to scientifically define its beauty (eg a certain proportion of sky to ground for example) but in the end you just have to look and see which grabs you the most.

Buying over the internet

A diamond’s certificate is a rather convenient thing for internet retailers because they can convince you that its therefore safe to buy unseen (as you know what you are getting) and what’s more you can compare prices between retailers. This isn’t true because each diamond is unique and you really need to sit down with an expert in a reputable company, and look at a selection of stones before making your choice – you will see that each stone is very different regardless of its grading and its certificate.