Advice, Facts

How Does Diamond Grading Work?

Whenever you buy an item of diamond jewellery, you need to understand how the grading system works. Diamond grading allows you to make an informed decision about what you’re buying.

Every diamond we sell here at Dubai Sparkle – and at any other reputable diamond seller – must go through an independent evaluation. This is very important for your peace of mind, so you know that the process has been completely honest and impartial. In this short guide we will discuss the key characteristics that are taken into account when grading diamonds.

Diamond grading works on a scale of 0-10. Unlike many grading systems, in this case the lower the number, the higher the quality – zero is the highest possible grade and ten is the lowest. But in order to really understand what this grading scale means, it’s important to understand how experts decide what makes a diamond really special.

Diamond grading is all about “The Four C’s” – Cut, Colour, Clarity and Carat Weight. The cut grade is the most important factor to consider, followed by colour, and then the other two factors.

If a diamond is graded 0 for cut and colour, is free from marks and blemishes and weighs 1 carat, its official grading would be 0/0/0 – 1.000 carat, and so on.

Contrary to popular belief, the cut of a diamond does not refer to its shape. Instead, this important part of the diamond grading is all about its overall proportions, polish and how symmetrical it is. This affects the overall appearance in three essential areas:

● Brilliance (how bright the diamond looks)
● Fire (the flashes of colour you can see when it moves)
● Scintillation (the flashes of light and darkness that can be seen when it catches the light or moves into darkness – AKA how much it sparkles)

When a diamond is made from a rough stone, the cutter must make an important decision between how the diamond looks, and how much it yields in terms of carat weight. A lot of customers favour a big diamond over a small one, but size isn’t everything. Often cutters are forced to sacrifice a diamond’s clarity over its weight, when in fact a smaller, very well cut diamond could be worth more. The Cut grade clearly sets out how well the diamond was cut, ranging from Excellent to Poor.

Diamonds are often considered to be colourless, but in actual fact most of them do contain a range of colors when closely examined. The closer they come to being completely colour free, the more rare – and therefore more valuable – they become (please note- this relates to “normal” diamonds, and not the ones that lie outside the standard colour range. Obviously coloured diamonds, such as red, pink and blue, are extremely rare and valuable in their own right).
Most diamonds that can be bought in the shops contain slight hints of gold, yellow and brown. The colour grading scale works by comparing the diamonds to stones of other colours under controlled lighting, and ranges from the letter D – meaning completely colourless, to Z, meaning very light.

Diamonds are formed deep within the earth, as a result of intense heat and pressure. Because of the rough and stressful way they enter the world, it’s common for them to be found with cuts and scratches. These are referred to as inclusions (found inside the diamond) and blemishes (marks on the diamond’s surface).

Clarity refers to the amount of blemishes and inclusions a diamond contains, which is why zero relates to the highest possible grade. It’s very rare to find a completely “flawless” diamond that’s absolutely free from blemishes or inclusions, so those obviously cost more money.

The Clarity Scale is decided under 10x magnification and contains 11 grades, from (FL) to obvious inclusions (I3), as follows:

  • Flawless (FL) – No inclusions or blemishes are visible to a skilled grader using 10× magnification
  • Internally Flawless (IF) – No inclusions, and blemishes can only be seen under 10× magnification
  • Very, Very Slightly Included (VVS1 and VVS2) – Inclusions are present, but difficult for even a skilled grader to see under 10× magnification
  • Very Slightly Included (VS1 and VS2) – contains small inclusions which are slightly easier to identify under magnification
  • Slightly Included (SI1 and SI2) – a skilled diamond grader can see the inclusions easily under 10x magnification
  • Included (I1, I2, and I3) – obvious inclusions that are easy for anyone to see under 10x magnification. These marks can also affect the overall look and transparency of the diamond to the naked eye

Even diamonds that look completely clear and blemish free usually show up at least a few marks under the microscope, and the majority of jewellers have never seen one that can be classed as truly flawless.

Diamond carat refers to the weight of the stone, and one carat is equal to 0.20 grams. The term “carat” historically comes from carob seeds, which were used as a measurement of weight in ancient times.
Every diamond is unique. Just because a diamond is big it doesn’t necessarily mean it will have a high carat weight, because the way a diamond is cut has a huge effect on how much it weighs. But as a rough guide, this is what you can expect a well cut diamond to weigh based on its width:

  • 0.2-carat diamond usually measures around 4.1mm
  • 1-carat diamond = 6.4–6.5mm
  • 3-carat diamond = 8.1mm

Different shapes can have an effect on how heavy a diamond looks, because the top of the stone is usually the visible part once it has been set into the jewellery. If you want a diamond that looks as heavy as it is, it’s worth considering a minimal setting that shows off as much of the rock as possible.

Although we may all dream of the highest possible graded diamonds, in most cases it’s only the extremely wealthy who can afford them. Every item of diamond jewellery is special, and you can still buy a beautiful piece on a small budget. Browse our range of certified, independently graded diamond jewellery today.

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