Diamond selection begins with the 4 C’s

Colour

This refers to the colour of the diamond. Diamonds are graded from letters D to Z however most people choose a diamond engagement ring within the D to J range. D is colourless and as you move down the scale, to J and below, yellow or brown colour hues become more prominent.

When diamond graders estimate colour they look at diamonds through the bottom, or pavilion, of the diamond. This is the only way to detect the tiny colour differences between one colour and the next.

An experienced diamond grader will only be able to estimate if a round diamond is colourless, near colourless or faint-yellow (as per the diagram) when looking at it normally through its top surface (or table). This should tell you something – these colour differences are very small. In fact, for round diamonds you could readily choose a J colour in order to get a bigger diamond for your budget.

With fancy shapes such as emerald cuts or even oval shape diamonds colour is much more noticeable. For these diamonds we recommend G colour or better if possible. You might find that D colour diamonds are very expensive in retail shops but this is because they are not commonly available on the high street. We often supply D colour diamonds at amazing prices and it is a lovely result for the buyer because it is the highest grade possible - it can't possibly be any better!

Diamond colour is very important but, in general, just as with clarity, there is a mid range which is perfectly acceptable. To compare diamond colours book a diamond consultation today.

Clarity

Again, it is not the case that an Internally Flawless diamond is beautiful and an SI2 diamond is ugly. As you will learn at our diamond consultations diamond beauty is always a matter of the cut quality. In fact, it is common to find I1 diamonds that are absolutely stunning with no inclusions that are visible to the naked eye.

Inclusions come in many forms – there are feathers which look like tiny white wisps, included crystals which are tiny diamonds within your diamond and then there are cavities which can appear black to the eye. These are the ones that you want to avoid because you might be able to see them even in a diamond that is SI1 grade. This is one of the main reasons why no one in the diamond trade will buy diamonds unseen. At our diamond consultations you can examine diamonds with a jewellers loupe and also in a special hearts and arrows viewing device which will help you locate inclusions.

Inclusions should not be viewed in a very negative light. Most inclusions are invisible to the naked eye and they are unique and natural parts of most diamonds. All diamonds are between six million and 1.5 billion years old, when they were growing in the intense heat and pressure required to create them, inclusions were a natural result of the process. The fact that higher clarity grades are more valuable is solely a reason of rarity, again for example, a VVS1 grade diamond and VS1 grade diamond with ideal cut grades will look equally beautiful.

Clarity is graded from IF, which is internally flawless, to I3 or P3, which is included or “pique” and has many visible inclusions. An internally flawless diamond is extremely rare and therefore extremely expensive. You need to work with a diamond specialist to ensure that you are buying a beautiful stone – just clicking and buying from a website is a risky move for such an important purchase.

Carat

The carat is the diamond industry's universally accepted measurement of diamond weight. The word comes from the carob seed which had a very uniform weight of 0.2 grams.

It is important to realise that carat is 'weight' and not 'size'. This is the reason why: Imagine an iceberg that weighs one tonne. A tiny bit shows above the water. But does the bit above the water tell you how close you can go in your Titanic before hitting it? No. Maybe the iceberg is really deep and thin or maybe it is really shallow and flat. The same applies to diamonds. You might get a 1 carat diamond that looks really small from the top down (the normal view) because all the weight is in the bottom or, to put it another way, it is a deep diamond.

Therein lies one of the secrets of the diamond world – deep diamonds are cheap diamonds and you need to make sure that you are buying an ideal cut diamond so that you are not ripped off. The reason why deep stones are significantly less valuable is that they display what it called “unplanned light leakage” resulting in a dull, dark and sparkle-less stone. And you can see why it is tempting for a jeweller to sell a deep diamond - he can still say it is the magic "1 Carat" and the unknowing customer might think they are getting a great deal because it certainly sparkled nicely when it was clean and new in the shop! More of these diamonds are sold than you might like to think.

We have seen some shocking examples from Antwerp and Ireland alike. A client recently wanted to upgrade a 0.75 carat, F colour, VVS1 clarity, princess cut because it looked really small. It was really deep and therefore from the top view looked much smaller than most 3/4 carat diamonds. The semi-educated buyer thought it was a bargain because it was VVS quality. On the contrary, those wiley Antwerp guys just offloaded a cheap stone knowing they would probably hear nothing more.

In general terms, however, carat weight indicates the size of the diamond. The bigger the number the bigger the diamond. For most people size really does matter, however, as with the shape of the stone, it is advisable to know what size suits your hand. The average diamond engagement ring is between 0.5 and 1.00 Carat. To compare prices for different diamond sizes - click here.

Cut

'Cut' actually refers to the shape of a diamond and it is also used to describe the perfection of the diamond’s cut or 'Cut Quality'. ‘Cut’, as it refers to shape, is obvious and the various shapes are shown below but the biggest factor affecting a diamond's beauty is the 'Cut Quality'.

GIA has recently started defining cut quality grades on their round diamond certificates and this is to help everyone know whether the diamond they are buying is ideal, premium or average. Whilst the commercial range of clarity and colour can have minimal effect on a diamond's beauty, cut quality has a huge effect. The “deep” diamonds described above would be called “Good” cut by GIA. What we are looking for are “Very Good” or “Excellent” cut grades.

This is another very good reason not to buy a diamond that is uncertified. Not only is it unclear what its true grades are, it is possibly also deep or poorly cut and therefore less valuable. A well-cut diamond will have beautiful sparkle and have great fire and lustre.

Please read some of our customer reviews to see the 4 Cs in action!