How do you choose the right diamond for your bespoke engagement ring?

When we’re talking about diamonds, it’s all about the four Cs. The cut. The colour. The clarity. The weight in carats. Each of these four factors define the quality and value of your diamond. Our knowledgeable and approachable team at FANCI Bespoke Fine Jewellery, based in Southampton, is passionate about helping you to find the right diamond for your ring and can show you a wide range of diamonds.

So, what do we mean by the four Cs and the impact each has on a diamond? Let’s find out.


Diamond Cut

By the cut of a diamond, we mean how well-proportioned the dimensions of the diamonds are and how the surfaces, known as facets, are positioned to create the sparkle and brilliance of the diamond.

The cut is generally recognised as the most important of the four ‘Cs’. This is because you could start off with the best diamond in the world but, without it being beautifully and expertly cut, its brilliance will be diminished.

The reason the cut is really important is because it determines how well the light can enter into the diamond itself. So, if the cut is classed as ‘excellent cut’, the light can go directly into the stone, back across the bottom, and back out at the top, meaning that you get a huge amount of sparkle. This is often described as the ‘fire’ of a diamond. If it's poorly cut, it means that the stone can be quite squashed down. The light simply can't enter and refract back out so you don't get the sparkle that you're looking for.

How well the stone has been physically cut is a process that is universally graded. Your diamond will come with a certificate specifying the quality of its cut. ‘Excellent’ is the best of the best, followed by ‘Very good’ then ‘Good’. The bottom grade is ‘Poor’.

Regarding its shape, which can also be referred to as its cut, the classic is the round brilliant stone. However, you can have your diamond cut into whatever shape you like – pear, oval, heart, square, oblong, anything you can think of.


Diamond Colour

The colour of a diamond is referring to how white the diamond is. The colour of a diamond is important to consider when you are choosing your bespoke piece of jewellery. For many people, it's down to personal preference of what they're drawn to. The metal setting and band can play a part too - a clearer, whiter stone goes well with a white metal like platinum. A warmer tone metal like yellow gold or rose gold could potentially be better complemented by a warmer toned stone.

There is a universal letter grading system that ranks the quality of a diamond’s colour. D is the highest grade, classing the diamond as completely colourless, and Z is the lowest grade which will show a quite noticeable yellow or brown tint. 

The colour of the diamond affects its overall price; the whiter the diamond, the higher the value.

Diamond Clarity

When we are describing diamonds, clarity is referring to how clear a diamond can be. Diamonds are made of carbon and, as they’re not formed in a perfect environment, you can get impurities within natural stones which normally appear as black or white marks within the stone. They might be hard to see with the naked eye but any marks will dull the stone and reduce its sparkling impact. 

Highly accomplished diamond cutters use their skill to minimise these marks and maximise the clarity and therefore the sparkle generated by your diamond.


Clarity is an important factor to consider because it can affect the overall appearance of the stone. If you have a stone that has a really high clarity grade, it means that you are going to get the ultimate sparkle. If your clarity grade is quite low down the scale your diamond might be quite dull, perhaps milky looking and it just won't have the fiery wow factor you expect from a diamond.

There is a scale that measures a diamond’s clarity. The top grade is Flawless (FL), and the bottom grade is Included (I1, I2 and I3). The lower down the scale you go, the more blemishes, or inclusions, the diamond will have. 

Regarding the impact of clarity grade on the price of a diamond, the clearer the stone, the higher its value will be.


Diamond Carat

A carat is a metric unit measure specifically for weighing a diamond. To give you a sense of perspective, a carat equates to 200 milligrams. Each carat is subdivided into 100 ‘points’ which means we can be very precise with our measurements to the hundredth decimal place. For example, a diamond that weighs 0.22 carats would be described as a ’22-pointer’. A diamond that weighs more than one carat is expressed in carats and decimals, i.e. 1.07 carats.

Carat weight can often be indicative of size, but it’s not always the rule as diamonds can be deep or shallow, making the size relating to its weight misleading.

The carat of the diamond is important as it gives you the opportunity to choose the right size that will best suit you and the ring you are designing, and to make a selection that fits your budget. 

All things being equal, the heavier the carat weight the more expensive the diamond will be as larger diamonds are rarer and therefore in higher demand. However, if a larger diamond scores ‘lower’ in the other Cs then it may not be as valuable as a lighter diamond with, say, a purer colour.

How can FANCI help me find my perfect diamond?

We have been working with diamonds for many years and would love to help you find the right diamond for you. As much as online shopping can be very convenient in many circumstances, when you are making such an important decision like choosing a diamond, you can’t beat seeing the real thing! 

Come into our Southampton store and marvel at lots of diamonds close up. We’ll explain the four C’s to you, and point out subtle differences by comparing different stones.

During your consultation, we will discuss your colour preferences and pick which colour will work best with the ring metal you choose. We will go through the available carat weight options available, choosing the one that will best suit your style and your budget.

We can examine the available stones and their different grades together. And, wherever possible, we will make sure you get an Excellent or Very Good cut grade diamond.

How can I contact FANCI?

We would love to help you to make the right choice for this important purchase. You can call us on 023 8020 1717, email us at or go to our website and complete our online contact form. Our expert and friendly team looks forward to hearing from you.