Diamond Grading

Understanding the Quality of Diamonds that you purchase

Diamonds are in essence a naturally forming stone derived from pure carbon.  It is one of the Earth's hardest minerals.

When it comes to shopping for a diamond ring, as an important and unique investment, for somebody starting out looking for their purchase you will see that prices differ dramatically, even with rings that appear to have the same stone size.  To understand why this is, the following grading categories are explained -  


Cut – The only manmade aspect of the 4 C’s is the Diamond’s cut which indicates how the Diamond is shaped in its size.  In order for the best light reflection the Diamond needs to be cut perfectly and without this, if its cut out of proportion it won’t reflect as well.

The most popular cuts are as follows –

Round Brilliant Cut

Princess Cut

Emerald Cut

There are also many other cuts such as Heart, Marquise, Cushion, Asscher, Radiant and Trilliant, Oval and Pear. 


Colour – This is one of the most important features of a Diamond in relation to value.  A colourless Diamond is a perfect example of this because its exactly that, it’s an outstanding white colour with no trace of any other tones.  This is known as a grading of D which is the best and highest quality colour grading.  As mentioned the top colour is D and this scale goes right down to Z colour grading which is yellowy in appearance.  Anything between D and H is a good quality colour and is classed as white and you will not see any hint of colour.  Grades I to L you will start to see a change in colour, typically a faint yellow shade.  Anything beyond grade M is going to show more obvious tone of yellow.


Clarity – This is checking for the amount of imperfections in the Diamond.  Most Diamonds do have flaws present, and it’s not necessarily a negative thing, as it’s what makes Diamonds so interesting and unique.  Most of these however are not seen with the naked eye and can only be spotted when using a x10 magnification eye loupe.  The way of determining the flaws is listed below –

FL – this means the Diamond is totally flawless.  There are no flaws at all and this is graded by using a x10 magnification.  These Diamonds are extremely rare and therefore are very expensive.

IF  -  this is when the Diamond doesn’t have any inclusions present, although a laboratory may see the odd blemish when looking very closely under a x10 magnification.

VVS1-VVS2 – this is when the Diamond is very, very slightly included.  They are however very hard to spot when using a x10 eye loupe.  This is still a very good clarity grading.

VS1-VS2 – this grading is when the Diamond is very slightly flawed.  They are more clear however when looking under a x10 eye loupe.  They are still classed as a good grade.

SI1-SI2 – when this grading is present, it means that the flaws are seen much more easily, but still with a x10 magnification.

I1-I3 – this means the Diamond does have quite a few inclusions present which can be seen with the naked eye.  These tend to be much less desirable especially in larger stones, as the Diamonds will lose their luminosity.


Carat – Carat indicates the weight of a Diamond and is one of the ways of valuing a stone (in conjunction with the other 3 C’s).  It’s not quite as simplistic as the size of the stone.  As an example if you had two stones of the same carat weight, but one was VS1 and colour grade E and the other was I2 and colour grade L the most noticable difference is the brightness of colour and the amount of inclusions present.  Therefore, one will have a higher value.


Any questions you have please feel free to contact us by email, and we will be happy to assist you.