Diamonds are one of the most sought after gemstone. They are beautiful and strong, making them the ideal stone to be used in various forms of jewellery. Since diamonds are so precious and high quality ones are so rare, it is important for you to know what you are getting when you are making your purchase. No fear! I am here to help! The grading scale that a great deal of jewellers, the one I work at included, use the scale developed by the GIA. What is the GIA? The Gemological Institute of America and it is recognized worldwide. Today I will help you all understand the 4 C’s of diamond grading used by the GIA. This way you can ask the right questions and understand your jeweller’s answers when you go to buy diamonds.
The first C of diamond grading we will talk about is the Cut. The cut of a diamond refers to the style of the diamonds facets. This reflects on how brilliant the diamond appears. The higher the quality of the cut, the more brilliant the diamond will look. It takes a very skilled lapidarist to get the facets correct. When looking for a diamond of high quality, you should look for diamonds which have symmetrical facet cuts. The grading scale that the GIA uses grades the cut from Excellent to Poor.
A quick detour on the look at the 4 C’s. Let us look at the Shape. You would not believe the number of people that confuse the cut of the diamond with the shape of the diamond. This graphic shows some of the most common diamond shapes. Certain shapes of diamonds may have several different ways to cut them. The most common type of diamond that we sell at the store I work at is called a Princess Cut diamond. What that means is that it is a square shape with Princess Cut facets. Square diamonds can also be cut with Step Cuts, Cushion Cuts, and Asscher Cuts. Rectangular shaped diamonds may have an Emerald Cut, Radiant Cut, Rectangular Cushion, or Baguette Cut. Most round diamonds today use a Brilliant Cut, but in the past round diamonds also had Rose Cuts and Old Miner’s Cuts. A fun fact about diamonds shapes is that certain shapes look bigger than what they are. Marquise shaped diamonds, which are my favorite stone shape, look massive! At the store I work at we have a two carat square shaped diamond and a 2 carat marquise shaped diamond. That marquise looks twice the size of the square one. Talk about more bang for your buck! Just saying!
Clarity is the next of the 4 C’s that we will look at. The clarity of a diamond is how clear and free of blemishes the diamond is. The GIA grading scale is at the left to give you an idea about the different grades of diamonds. Since diamonds are formed inside the Earth it is very rare to find a diamond that is flawless. Most diamonds will have some imperfections called inclusions. Do not be alarmed if you diamond has a tiny black spot inside of it! Tiny black spots on the inside of a diamond are flecks of carbon that did not have the chance to be fully compressed before it was mined and it is completely natural in a diamond. Think of it as a small piece of time forever frozen in your diamond. Science for the win! Awesome!Back on track of the 4 C’s.
The Carat of the diamond refers to how much the diamond weighs. It is not necessarily an indicator as to how big the diamond will be. How does the carat scale of weight work? Think of a carat as a U.S. Dollar. A U.S. Dollar is divided into 100 pennies or 100 cents. A single carat is divided into 100 points. So, if you have a diamond that is listed as 1.25 carats or the jeweller tells you that it is a one and a quarter carat diamond, it means that the diamond is one carat and twenty-five points. To give you a bit of prospective on how much a single carat weighs in terms of an actual weight, a single carat diamond will weigh 0.2 grams. That is about the weight of a standard size paperclip.
Diamonds come in many different colours! Colour is one of the easiest of the 4 C’s to understand. The most desirable colour is a completely colourless diamond. They are also the rarest. Most jewellery stores carry
colourless to near colourless. However, the other white diamond shades shown in the chart are also available most places if you are looking for a lower priced diamond. The GIA uses a grading scale that starts at a completely colourless D at the top to a light yellow Z at the bottom. This scale is only used for white diamonds.
Diamond are not just available in shades of white! As mentioned above, diamonds come in all colours. When a diamond reaches a colour more vibrant than a Z or has another colour, like shown on the diamond colour chart, it becomes known as a Fancy Colour diamond. There are no standardized scale for these fancy diamonds to be graded on colour. Be aware that some coloured diamonds are irradiated. This is a way to bring out its colour and make it more vibrant. it is a permanent treatment and the colour will not fade.