What is Diamond Certification?

Diamond certification, also known as a Diamond Grading Report, is the official evaluation of the various qualities of a diamond. No two diamonds are the same, as they all vary in size, quality and grade. Diamond certification enables a buyer to have a clearer and better understanding of the diamond they are purchasing, and how it stands compared to other diamonds. Because of the various differences in all diamonds, diamond certification offers buyers a way to determine the quality of a diamond.

Qualities that are analysed in a diamond certificate include:

  • Dimensions
  • Clarity
  • Symmetry
  • Cut
  • Colour
  • Carat weight
  • Other diamond characteristics.

The report will also include an exclusive Report Number, a Laser Inscription Registry Number and various security features. This certification is a way to distinguish and analyse a single, loose diamond specifically.

There are several reputable groups that provide certification, which is used to grade the diamond and provide an accurate review for potential buyers about the quality of the stone.

These groups include:

  • The Diamond Certification Laboratory of Australia (DCLA)
  • Australian Diamond Grading Laboratory (ADGL)
  • Scientific Gem Testing Laboratories (Auscert)
  • Gemmological Institute of America (GIA)
  • Gem Studies Laboratory (GSL)
  • American Gem Society Laboratories (AGSL)
  • HRD Antwerp (HRD)
  • Independent Gemmological Laboratory (IGL)
  • International Gemmological Institute (IGI)
  • International Institute of Diamond Grading & Research (IIDGR)

What is the difference between certification and an appraisal?

While diamond certification looks at the scientific qualities of the diamond, an appraisal only gives a monetary value to a diamond. Usually, appraisals on set stones are less accurate than loose diamonds, as it is easier to spot any imperfections and flaws in loose diamonds.

All diamond purchases should be evaluated and certified to know that the price you’re paying for the diamond is correct, and also for insurance purposes.

Why do you need diamond certification?

Many people would argue that diamond certification, or a Diamond Grading Report, is unnecessary. This couldn’t be further from the truth. You should never accept a diamond without a Diamond Grading Report as otherwise you will not have an official way to determine the quality of the diamond.

The report will offer you peace of mind when you make your purchase so you know exactly how authentic the piece is and the official quality of the diamond. If diamond certification is not offered during the sale, don’t be afraid to ask for it. This is your investment, so you need to be happy with your purchase.

If you ask for the certification and it isn’t supplied, don’t be afraid to walk away from the sale.

Key aspects of diamond certification?

When a diamond is certified, there will be four main areas that are analysed for certification purposes. These are:

  • Cut – When a diamond is well-cut, it directs the light through the crown better. This gives it the ‘sparkle’ diamonds are known for, and results in it appearing brighter to the naked eye. Cut is graded anywhere between excellent and poor.
  • Colour – Colour refers to the colourlessness of the stone. The less colour a diamond has, the more value it holds. The exception to this is fancy coloured diamonds, such as blue and pink diamonds. There are diamonds with slight hints of yellow and browns, but the most valued colouring of diamond is completely colourless.
  • Clarity – Clarity of a diamond refers to any internal or external blemishes that may be in the diamond. Because diamonds are formed within the earth under extreme pressure and heat, it’s natural that some diamonds will receive some form of “birthmark”, which can either be internal (inclusions) or external (blemishes). Of course, those which are flawless are worth substantially more.
  • Carat – Diamonds are weighed in metric carats. One carat of diamonds weighs 0.2 grams, about the same weight as a paperclip. Even a fraction of a carat can change the price of a diamond substantially. Diamonds that weigh more or less than a carat are measured in carats and decimals.

There are scales for each quality and the diamond is graded accordingly.

Why should you always buy a diamond with certification?

The problem with a diamond without certification is there’s really no way of knowing the quality of the diamond you’re hoping to purchase. Without a certificate, it’s easy for a jeweller to say the diamond is higher quality and the diamond could even be “enhanced” in some shape or form. Yellowish colouring, internal fractures and any other aspects that aren’t seen by the naked eye are all usually discovered during grading, and would normally be listed in the certificate. Some diamonds can also be drilled to get to internal inclusions, which of course means the diamond is worth a lot less than a diamond that hasn’t been drilled. And yellowing diamonds are sometimes heat treated to make them whiter, which in fact makes them more brittle and fragile.

This is why purchasing diamonds should always include a diamond grading certification so you can know exactly what you are purchasing.

How can you tell if a certificate is intended for that particular diamond?

With all certificates, there will be a serial number for the certificate and corresponding diamond. Sometimes this number is then laser engraved onto the diamond girdle. However, a professional jewellery thief or an unscrupulous jeweller knows they can remove this serial number with a repolish of the girdle.

The best way around this is to hire a third-party analyst to take a look at the diamond and the corresponding certificate to determine that the diamonds’ certificate is legitimate.

Does self-certification count?

The short answer is no. When getting a diamond certification, it should always be from a reputable and recognised laboratory.

Diamond certification is necessary for peace of mind

Whether you want to buy a special gift for a loved one or you are looking to improve your personal investments, buying the right diamond with the appropriate certification means you’ll be able to get the best quality diamond for your money. As there are many differing factors to diamonds and their quality, getting a diamond with a certification from a reputable leader in the industry is always very important. That way, you can rest easy knowing that you’re getting the best diamond you are paying for.