The Four ``C's``
The legendary 4 C’s of diamonds are: Colour, Clarity, Cut and Carat. Collectively they are used to grade and describe the quality of an individual diamond. Essentially these qualities, when described by a gemmologist, help to determine the value of a diamond.
The Gemmological Institute of America (G.I.A.) established the 4 C’s to create standardization in the language used to describe the various qualities of diamonds. Before the establishment of the 4 C’s there were many different systems of terminology for describing the qualities of diamonds. Some systems were popular in certain geographic areas and others were popular in another place. It’s easy to see how that could get very confusing!
Below we explore each category in further detail. The information we’ve provided here is essentially a primer, for further information we highly recommend the G.I.A. website. If you’re interested in gemstones, there’s no better place!
Colour
Colour is the only diamond quality that is going to be directly affected by everyday wear. Nothing will actually change the colour of your diamond but sometimes grime can build up under the setting and mask a diamond’s true colour. We try to remember to take off our rings when we are putting on make up or applying cream but, inevitably, we all forget sometimes. Of course, all it takes is a quick scrub to have your stone shining it’s brightest, true colour again!
The scale begins at D and ends with Z. Letter grades D through F are considered ‘colourless’, G through J ‘near colourless’, K through M are ‘faint’, N through R ‘very light’ and S through Z ‘light’. Generally I recommend stones graded H and above as I find I can see a faint yellowish hue around the J/K grades. That being said we’ve seen some spectacular J/K graded stones so you just never know until you see it!
Clarity
Clarity refers to how ‘clean’ a diamond is, or in other words, if there are – or are not – inclusions present in the stone. Inclusions can be anything from black bits of carbon to tiny crystals of other minerals to little feather-like marks. Inclusions are actually a good thing because they can serve two purposes. Once you know the inclusions of your particular diamond they can be used as an identifier. Also, the presence of inclusions indicate the natural origin of your stone.
The scale begins with Flawless (F) and Internally Flawless (IF) which are very rare grades. Next is the Very, Very Slightly Included (VVS) category which have inclusions so small even a diamond grader has trouble seeing them. At the Very Slightly Included (VVS) category inclusions can be seen at 10 times magnification but they are very minor in comparison to the Slightly Included category (SI) where the inclusions can be seen quite clearly at 10 times magnification. Often the SI category is referred to as ‘eye clean’. Finally the Included cateogry (I) will have inclusions that are visible to the naked eye. We see the most value and quality in stones graded SI and above.
Cut
Cut is the only quality that really gives us humans a chance to shine, no pun intended. All of the other qualities, colour, clarity and carat are determined by nature. Cutting the facets of a diamond requires great skill and many years of training. Cut is arguably the most important quality because a diamond with a higher grade cut will reflect light, creating beautiful ‘fire’ regardless of the colour, carat or clarity of that diamond.
The GIA cut scale labels the highest grade as ‘Excellent’ but you may also see ‘Ideal’ listed for some diamonds. They are comparable. The next grade is ‘Very Good’, then ‘Good’, ‘Fair’ and ‘Poor’. We recommend diamonds with a Very Good cut or above.
Carat
Carat may be the most familiar diamond quality for most people. Terms such as ‘half carat’ or ‘one carat’ are common standards that are used by popular culture but a lot of people can’t actually visualize the equivalent diametre size. It’s important to note that carat is a weight measurement, not a dimensional measurement. A one carat stone is roughly equivalent to around 6.5mm in diametre but each individual will have slightly different measurements.
There is no carat size that is a ‘standard’ or a ‘minimum’. Every and all diamonds are unique and beautiful. The best diamond is the one that is right for you.
Diamond Shapes
The most important thing to understand about diamond shapes is that it is not the same thing as cut. Diamond shape is not a grade in the 4 C’s. Diamond shape describes the form in which the stone has been created. Sometimes particular shapes such as ‘Asscher’ or ‘Princess’ also have a special cut that is only used for stones of a particular shape. Whereas a brilliant cut could be used on both round and oval shaped diamonds or a step cut could be used on both baguette and emerald shaped diamonds.
There are a multitude of diamond shapes available and new ones are being innovated all of the time. The most common shapes that are used are round, oval and square. Antique cushion cuts with rounded corners in either square or rectangle are also popular right now.
For certain shapes there are considerations you will want to make when setting to protect the stone. For example, for shapes with sharp, vulnerable corners such as square princess or marquis you’ll want to ensure that those corners are covered and protected in the setting. Another example would be the soft square antique cushion shaped stone. If using a prong setting, the stone could potentially shift in the setting due to its shape so it’s better to use either a double prong or bezel to set this shape of stone.
When selecting your diamond shape you’ll want to keep in mind which one works best for your design. Some diamonds definitely work better than others for some designs. If you prefer a unique shaped stone such as a marquis or trillion it is better to first select your stone then create the design for your jewellery piece.
