What You Need to Know Before Buying a Diamond


For most, assessing diamonds only becomes relevant when they are on the hunt for a diamond ring. It appears complicated as the terminology used by jewellers seems far too advanced but it shouldn’t be this way. The Gemological Institute of America, referred to most commonly as the GIA, created the 4Cs: Colour, Clarity, Cut and Carat Weight as a universal method for establishing the quality of any diamond, anywhere in the world. The 4Cs means two very important things: 1) diamond quality can be communicated in a universal language, and 2) diamond-buying consumers can know exactly what they are about to purchase (GIA, 2020). Understand these 4 very simple terms and you will be much more educated when discussing your next diamond ring.



When it comes to diamonds, the less colour, the higher the grade, this simple colour scale classifies diamonds from D (colourless) to Z, which are light yellow or brown. Each letter grade represents a range of colour, and is a measure of how noticeable that colour is. Purely colourless diamonds are very rare and most diamonds used in jewellery are nearly colourless with extremely faint tints of yellow or brown. The GIA cleverly assembled a set of master stones, representing the colour grades on the scale seen below. This makes it easy for graders to sort diamonds by comparing each diamond to a master set. Now here is the official colour grading scale.


The second C is clarity. Because diamonds form under tremendous heat and pressure it is extremely rare to find a diamond, with no internal or surface reaching inclusions. Inclusions are a by-product of its formation and actually help geologists separate natural diamonds from synthetics and look alikes. the GIA clarity scale includes grades, ranging from ‘flawless’ to ‘I3’. ‘Flawless’ indicates that there are no inclusions or blemishes visible at 10 x magnification, a grade of ‘I3’ is for diamonds with inclusions that are obvious to the naked eye. Jewellers and diamond graders use a 10 x magnification loop, and a microscope to see the inclusions since no two diamonds are exactly alike. This unique plot helps identify a particular stone. Seen here is the clarity grading scales.


The third C is cut. The cut scale is used for round brilliant cut diamonds only and consists of five grades, ranging from excellent to poor. You may think of cut is the shape of a diamond, like square cut for round. However, there is much more to cut than the basic shape like how a diamond is cut and polished directly affects the amount of sparkle and brilliance that comes off the stone when it interacts with light. The diamond proportions affect its light performance too, which in turn affects its beauty and overall appeals.

Carat Weight

The fourth C is carat weight. One carat equals 200 milligrams, or one fifth of a gram in weight. Larger diamonds are significantly more rare than smaller diamonds. So, in theory a single one carat stone, would be worth more than four 0.25 carat stones put together. However, the value of a diamond is determined by considering all of the 4 C’s so bigger is not always better.

So, let’s take you through the grading process of this diamond I happened to have on my desk while writing this blog. This is a pear-shaped brilliant cut diamond. The colour grade is evaluated to be ‘G’ as seen in the centre of the GIA certificate meaning it is near colourless. The clarity grade is VS2 signifying it is very very slightly included barely visible under intense magnification. As I mentioned previously the cut grade is only applicable to round diamonds so this diamond does not have a cut grade on the certificate. And lastly the carat weight is 0.60carat making it a perfect size for a centre stone. I hope you have gained knowledge from this blog and you know what you're talking about the next time you discuss diamonds! To discuss about diamonds or anything jewellery please make contact with us through our website, Instagram or Facebook.

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