Diamond Grading: The 4 C’s of Engagement Rings

Understanding diamond quality can best be done by knowing the cut, clarity, colour and carat of a diamond when buying an engagement ring.

To help you better understand this we’re detailing everything you need to know about the 4 C’s, including a diamond grading chart so that you can be well informed when you begin your hunt for the perfect ring.

Lady showing her diamond ring grade and quality.


The cut of a diamond is an extremely important factor to consider when purchasing an engagement ring, some would say the most important. This is because the proportions of a diamond will determine the diamonds brilliance or what we generally refer to as its sparkle. How the diamond has been cut will greatly affect how light travels within it and moreover affect the diamond quality. A diamond cut with the proper proportions has light returned out of the top of the diamond. If the diamond has been cut too shallow or too deep, some of the light will be lost out of the sides and bottom which will impact the diamonds beauty. The symmetry and polish of the diamonds facets will also affect the diamonds sparkle.

Diamond Grading Chart for Cuts

Excellent: This cut reflects nearly all light that enters the diamond and has been cut to amplify the diamonds brilliance.

Very Good: A very good diamond reflects most of the light that enters the diamond. Under normal lighting conditions this cut appears very similar to that of the Excellent Cut, yet has a slightly lower price.

Good: Good cut diamondsreflect a majority of the light that enters the diamond providing an above average appearance. Diamonds within this grade provide great value for those looking to stick to a budget yet not wholly sacrifice the brilliance of the diamond.

Fair: A fair cut diamond reflects a modest amount of light, losing much of the light that enters the diamond out of the sides or bottom. Typically, you can get away with a fair cut for lower sized diamonds.

Poor: A poor cut diamond will reflect only a small proportion of the light that enters the diamond, losing most of the light out of the sides and bottom. The lack of sparkle can make these diamond cuts appear dull.


Grading of engagement diamond ring

The colour of a diamond is generally considered the second most important diamond classification after cut when selecting a diamond. Diamonds are graded on their lack of colour. In a white diamond, the presence of yellow will lower the diamonds value. As such the less colour present in a diamond, the higher its colour grade. The colour grading scale ranges from D to Z, with D being colourless and Z a pale yellow.

For the untrained eye colour can be hard to determine, especially once the diamond is in its setting. As the carat weight of your diamond increases, colour becomes more important. This is because colour becomes more visible the larger the diamond.


Diamond Colour Chart

D     E      F G   H   I    J    K    L   M        N – R        S – Z
Colourless Near Colourless   Faint Colour Very Light Colour        Light Colour



Diamond ring on finger, zoomed in to display clarity of the diamond.

The clarity of a diamond refers to the number and size of the natural imperfections that are present on and within almost all diamonds. The diamond clarity grading has a greater effect on its price rather than its unmagnified appearance. Diamonds with the least imperfection and blemishes receive the highest clarity grades. Diamonds with numerous or substantial imperfections sparkle less as the flaws interfere with the path of which light travels through the diamond.


FL Flawless: No internal or external imperfections under 10x magnification.
IF Internally Flawless: No internal flaws under 10x magnification. May contain tiny blemishes on the diamond surface visible to a skilled grader under 10x magnification.
VVS1- VVS2 Very, Very Slightly Included: Very difficult to see imperfections under 10x magnification, imperfections are invisible to the eye.
VS1-VS2 Very Slightly Included: Imperfections are visible under 10x magnification, typically not visible to the naked eye. Some VS2 inclusions may be visible to the untrained eye in good conditions, this is however rare.
SI1-SI2 Slightly Included: Noticeable imperfections which are visible under 10x magnification and may be visible with the unaided eye.
I1 , I2, I3 Included: Obvious imperfections that are almost always visible to the naked eye.

Engagement ring displaying grade and quality of the diamond.


The carat of your diamond engagement ring refers to its weight not its size, something that can sometimes confuse a lot of people. A carat is a weight measuring unit used internationally to calculate a diamonds weight. To determine your diamond carat size you must also consider the distance across the diamond as well as the carat weight. This is because once a diamond is set within engagement ring designs we mainly see the top of the diamond.

The cut of the diamond can also affect the diamonds appearance, a well cut diamond can appear larger than a poorly cut diamond due to the amount of light being reflected. With this in mind it is possible to have a lower carat diamond that has a high cut grade appearing larger than a diamond which has a larger carat weight but lower cut grading, which may visually impact the diamond quality.

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