Diamond Buying Guide – The 4C’s

To put it simply the 4C’s are how a diamond is graded, they are colour, clarity, cut and carat weight. All these factors together determine a diamonds value and how rare it is.

Here at H Hogarth we believe that although very important the 4C’s should not be the only factors you take into consideration when choosing a diamond. A diamond is natural gemstone and therefore each one is unique. When buying diamonds, we also use our eyes to determine the beauty of each and every diamond. When you are choosing your perfect diamond, we recommend looking into the 4C’s, but we always say choose the diamond you fall in love with, the ring that’s perfect for you, the one you will enjoy wearing. At the end of the day the diamond grading report isn’t something you wear. We have a range of diamonds to choose from to suit every budget.

The best part of our job is helping you choose those particularly important pieces of jewellery. Whether it is an engagement ring or a birthday gift.  We are here to help and guide you.


So what is diamond colour? It is the lack of colour.

Diamonds are graded from D to Z. D a colourless diamond, is the highest grading, these are the rarest and therefore the most expensive. As you go down the colour scale the diamond develops a yellowish, brown tint. Many of these diamond colour distinctions are so subtle that they are invisible to the untrained eye. However, these distinctions make a difference in diamond quality and price.

Without comparing side by side it is very difficult to see the difference between a D colour diamond and a G colour diamond. However, the price between the two colours will be different. This is something to bear in mind when you are choosing your diamond. With careful examination you will see the difference when they are side by side. At H Hogarth we suggest choosing a colourless or near colourless diamond, all our new diamond stock is between D and I colour.


Diamond clarity is the absence of blemishes and inclusions. Inclusions and blemishes are natural and are formed when the diamond is created. Diamonds are created as the result of carbon being exposed to extreme heat and pressure deep within the earth. Amazing really something so beautiful can be created in that way!

The clarity grade as above goes from Flawless down to Included. From slightly included 2 (Si2) and above inclusions can only be seen under 10x magnification. As you go from VVS1 down to Si2 the inclusions become easier to see but only under 10x magnification. An included diamond with a grade I1, I2 or I3 has inclusions which may be noticeable to the naked eye and may affect the diamonds brilliance.



A diamond cut is how well the facets reflect the light. This is most complex and difficult to analyse of the 4C’s. It is determined by symmetry, polish and proportion. You may be wondering why a diamond cut is important? It is such an important part of a diamond as if the diamond has a poor cut it may appear lifeless with no sparkle even if the diamond has a high colour and clarity. Below you will see that the diamond cut is graded from excellent to poor.


Carat Weight

Diamond carat weight is often confused with the size of the diamond even though it is in fact the weight of the gemstone. Carat weights can look different across the different diamond shapes such as round brilliant cut, princess cut, radiant cut, emerald cut, marquise cut or oval cut. You can have two diamonds with the same carat weight which will look a different size. This is because although the two diamonds weigh the same, they will have difference proportions, for example one may be cut deeper. A carat is divided into 100 points, you will often hear a jeweller refer to a diamond below 1 carat in points. For example, a 0.50ct diamond may be referred to as a 50-point diamond or half a carat. This is just another factor that determines a diamonds price along with the other four C’s. A diamond with a higher carat weight does not necessarily mean it is better or more expensive.

Hopefully, this blog will have given you an insight into the 4C’s and will give you a bit of background information about diamonds and help you choose your perfect diamond. The 4C’s are an important part of buying a diamond however don’t get too bogged down by overloading yourself with so much information, after all buying a diamond should be a romantic and exciting experience. Make sure you are choosing a diamond you love and that you think is beautiful. After all it is going to be worn by you or a loved one, so it really is the most important part of buying a diamond.

As traditions evolve, diamonds remain an everlasting symbol of love.

If you have any questions about this blog or anything relating to diamonds, please do contact us by using our contact form or giving us a ring 01539 722166.

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