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Diamond Certificates

What is a Diamond certificate?

A Diamond certificate is a report created by a team of gemmologists to evaluate the quality of a diamond. This is also known under a few different names:

  • Diamond Grading Report
  • Diamond Dossier
  • Diamond Quality Document

The gemmologists will evaluate the diamond for its dimensions, carat, clarity, colour, polish and symmetry. There will also be a few further specifications taken from a diamond to complete the certification process. Tools used to evaluate the diamond are jeweller’s loupes, trained eyes, microscopes and other industry standard tools.

Why do I need a diamond certificate?

A diamond certificate is your proof of purchase. You will require this, along with a completed valuation so that you get your item correctly insured. Purchasing a diamond without this will result in difficulties of getting your jewellery protected.

What types of certificate are there?

There are ranges of diamond certificates you can select from, some are well recognised in the trade while others are not. However please note if you purchase any of these certificates your diamond, your insurance company will accept them 100%.

Types of Certification


Established in 1931, GIA is the world’s foremost authority on diamonds. After revolutionising graded the GIA has continued to provide unbeaten quality and service worldwide.

The GIA laser inscribes many of their diamonds (post January 2006) to ensure each matches the applicable certificate. You will need a loupe of 20x magnification to see this, failing that you will require a microscope. We have one available in store should you wish to view the inscription, however this is another added guarantee for any customer purchasing a diamond.

You can get more information on the GIA by visiting their site here.


The IGI was established in 1975 and to this day is one of the oldest based in Antwerp. They’re one of the largest grading laboratories with offices in Antwerp, New York, Hong Kong, Mumbai, Bangkok and many more.

You can get more information on the IGI by visiting their site here.


The AGI was founded in 1958 in the historic city of Antwerp, Belgium. With the city of Antwerp being synonymous with diamonds, it made the perfect base for a worldwide grading laboratory. They also have offices in the United Kingdom, Mumbai and many more. Another interesting fact is that they were the first grading laboratory to establish a base in the United Kingdom.

You can get more information on the AGI by visiting their site here.


The gemmological institute of Europe was established to protect customers when buying or valuing their diamonds, precious stones and precious jewellery. GIE is an independent foundation with offices around Europe and the world. GIE has been serving the international diamond industry for more than 30 years. GIE operates various services dependant on the individual laboratory. However all GIA laboratories offer core services : Diamond Lab, full diamond grading laboratory , which is respected worldwide by the diamond industry and by the general public alike; Precious Stones Lab; Jewellery valuation service. In addition the GIE invest heavily in research and development to counter the growing use of Laboratory Enhanced Diamonds. GIE stands for quality, tradition and the highest standards. Regular meetings are held with laboratory directors to ensure the current equipment is up to date and that only the highest standards are offered by their laboratories.

You can find out more about the GIE here:

I noticed you also offer a second level of certification, what is this?

These diamonds are certified in a slightly different way to the GIA/IGI/AGI diamonds. These diamonds are purchased in parcels containing 50-100 stones simply marked SI and D-G for example. These parcels will then be inspected to see if the diamonds inside are of a good quality. We only select the best stones from these parcels. These diamonds are then sent off to IDGL laboratory to be independently certified. When they return to us they’re fully certified along with all the applicable documentation.

The advantage of buying diamonds this way is the way they’re priced. We buy these at a set price regardless of if the diamonds is an SI1/D or an SI2/G. This allows us to price these diamonds at a far more competitive price; we then pass the savings on to you.

Should I buy an uncertified diamond?

The short answer is no. If you’re purchasing a single diamond that is 0.30ct or above you should expect to receive a diamond certificate. For diamonds that are smaller than this you should expect to receive a jewellery appraisal to cover the characteristics and replacement value for these diamonds. If you do purchase an un-certified diamond you may think you’ve got an amazing price, however there is no 100% proof that what you have brought is accurate, you will also find it extremely hard to get un-certified diamonds insured. Please be very careful!


Which certification is for me?

Picking a certificate can be a tricky decision. With so many choices, all with the similar combination of three letters it’s easy to get confused. However by reading this section you will be able to make an informed decision on which certification is for you.

What is the difference?

The most trusted diamond grading laboratories are The Gemmological Institute of America (GIA) is the world’s foremost authority on diamond certification, International Gemmological Institute (IGI), Antwerp Gemologische Instelling (AGI), Hoge Raad voor Diamant (HRD) and (EGL USA) European Gemmological Laboratory.

Out of the five above mentioned organisations the three we recommend at diamond heaven are:

  • GIA
  • IGI
  • AGI

Out of the three, The GIA is widely known to be the world’s foremost authority on diamond grading, they are known for being the strictest of them all.

Each of the labs has their own format for grading, whether this is in the layout of the certificate or the tools used to assess the diamond. As each lab has it’s own standards it is not uncommon for there to be a difference in grading. With colour and clarity being two of the key factors in the cost of a diamond you can sometimes see up to two grades difference between them. The table below shows you on average what we expect the differences between the laboratories to be.

In-house Certificates.

We highly recommend that you DO NOT purchase any diamond of 0.2ct or above that come with an ‘in house certificate’. These in no way follow any sort of grading guidelines.

Colour Comparison

Colourless DD +D +D +D +D +
Near ColourlessGFFFFE +
Faint YellowKJJJJG
Very Light YellowMLLLLI
Light YellowRQQQQN

PLEASE NOTE: This is simply a guide as to how we expect the grading to differ depending on the grading lab. This is solely based on our buying experience. If you’re unsure we suggest contacting us or visiting our store where we can show you in more detail.

Clarity Comparison

Eye CleanVS2 VS2 VS2 VS1VS1VVS1/VVS2
80% Chance of being Eye CleanSI1 SI1 SI1 VS2VS2VVS2/VS1
80% Chance of being Eye CleanSI2 SI2 SI2 SI1SI1VS1/VS2
40% Chance of being Eye CleanI1 SI3 SI3 SI2SI2VS2/SI1
Not Eye CleanI2 I1 I1 SI3SI3SI1/SI2
Not Eye CleanI3 I2 I2 I1P1SI2/SI3
Not Eye Clean I3 I3 I2P2I1

PLEASE NOTE: This is simply a guide as to how we expect the grading to differ depending on the grading lab. This is solely based on our buying experience. If you’re unsure we suggest contacting us or visiting our store where we can show you in more detail.

A diamond certificate is an evalution of the diamond that is done by an independent company confirming the colour, clarity and carat.