The Basics of Carat and Clarity of a Diamond

Diamonds are assessed on the 4 C's, here we explain about carat and clarity of a diamond.  When we design our bespoke jewellery including engagement rings we explain the characteristics of a diamond so you can make a more informed decision about the diamond you choose from our selection.


The 4 C's





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The Carat Of A Diamond
Carat quite simply is the size of diamond. Each significant diamond weight has an optimal width, please see chart below. People are surprised to see that there isn’t much difference between stone sizes. Firstly with any aspect to jewellery it is surprising how much of a difference a fraction of a millimetre can make on the look, impact and design of a piece of jewellery. Secondly, people often forget that carat relates to the diamond as a three dimensional form. When the diamond, the April birthstone, becomes wider it also becomes deeper and this represents the total carat weight of the stone. I mentioned significant sizes with diamonds, in some cases these are ‘magic numbers’. These are diamond sizes where the price suddenly increases I.E at 1.00 carats the price increases dramatically as people like to say they have a carater on their finger, therefore their demand for these on the diamond market is greater and the price reflects demand and the rarity. Other magic numbers are 0.50cts, 0.75cts, 1.50cts and you get the picture.

An image to illustrate the carat weight of a diamond 

Carat Weight chart in relation to millimetres.

The Clarity Of A Diamond

Clarity is as per the definition; how clear something is. With respect to the clarity of a diamond are there any marks or imperfections within a stone? Diamonds are pure carbon compacted over a long time under immense heat and pressure to create one of Mother Nature’s beauties.

 Where an area of diamond didn’t have quite the right heat or pressure it can leave imperfections and impurities, or a natural finger print some say. Those imperfections or natural characteristics can vary in size, be different colours, be situated in different areas of a diamond and these aspects govern how clarity of a diamond is graded.   There are many different types of inclusions from a pin point, feather, crystals and each has its own set of characteristics but fundamentally the clarity of a diamond is assessed on how obvious that marking is.

An illustration to show the clarity of a diamond


Diamonds, the April birthstone, in the I range are often referred to as Included or ‘pique’ and they have inclusions visible to the naked eye. SI1 clarity grade and above (small inclusions) needs a 10 x magnification and a trained eye to view the inclusions. The further up the grading scale you go the inclusions become fewer and fewer, more and more discrete and smaller and smaller in size. In some occasions due to the way the diamond is cut, the type and placement of an inclusion means that it reflects onto other facets of the stone internally. This effects gives you the look of having far more inclusions than is actually physically in the stone, as this effects the sparkle we avoid using reflectors (we haven’t used one to date). Some inclusions are solely internal whilst others can be surface reaching. When an inclusion is surface reaching further attention needs to be paid to the stone as the jeweller needs to assess if there are any risks to the stone when setting it.  


We keep harking on about finding a jeweller to trust as it’s really for your own protection.  There is a lot of information to absorb with regards a diamond, they truly are a mathematical equation when it comes to the cut, clarity of a diamond and all the other variables of the other 4 C's, diamond buying can truly be a minefield when you don’t know what you are looking for. 

Contact origin 31 to discuss your own bespoke jewellery

Due to the varied choices with diamonds we don't recommend buying through online websites, you can only truly see what you are buying when you see it in the flesh, see the 'make' of the stone, see the sparkle or as we specialists call it the 'life'.  We have been sourcing diamonds and assessing the 4 C's for over 22 years and source our ethical diamonds to meet with our clients expectations, where possible we like to show our clients their loose stones to put into context what they are buying and be a part of story, working through their custom design such as an engagement ring every step of the way.  If a client isn't available to view their stone then the wonders of technology allows video calling, by what ever means our clients are part of the design journey from start to finish.  

If you would like to understand our bespoke jewellery process a little more or to view some of our diamond pieces, you may want to have a look at these links;