Buying the Right Diamond: York’s Guide to the Four C’s

Formed deep within the earth’s mantle under unimaginable pressure and immense heat, diamonds are among the rarest naturally-occurring stones in existence. You may already know that diamond is the strongest natural material on earth, but did you know that it’s also one of the oldest, with most naturally occurring diamonds aging somewhere between a mind-blowing 1 and 3.5 billion years old? Diamonds are, in every sense, veritable natural wonders and it’s all too plain to see why they’re regarded as the universal symbol of purity, luxury and everlasting romantic love.

Regardless of your position, buying one of these incredibly precious stones can be a little overwhelming. There are a myriad of different diamonds to choose from, and each has its own distinct character and class. Diamonds also vary quite considerably in value and quality, so when it comes to purchasing one of these incredible rocks, it pays to know a little bit about what your buying into. Let’s be honest, diamonds aren’t cheap, and you’ll want to make sure that you’re getting the best possible product for your money.
When discerning the quality of a diamond, there are four important factors to consider: Cut, Colour, Clarity, and Carat. Jewellers call these the four C’s, and they are your best guide to ensure that you end up with the quality of diamond that you and your cherished loved ones deserve.

York's Guide to The Four C’S:


The cut of a diamond refers to the angles and proportions of its form, and is one of the most important factors to consider when buying. Whilst in essence, it refers to the general shape, a diamond’s cut can be further broken down into two distinct factors.

The first aspect of the cut refers to the physical form of the diamond. The options here are multitudinous and varied, and your choice will largely be defined by personal taste, but it is worthwhile talking to your jeweller about which cuts will compliment specific pieces of jewellery. The chart below exemplifies some of the most common and popular shapes available.



The second aspect of cutting refers to the various minute surfaces and angles created on the rough cut diamond and how these are positioned in relationship to one another. Known as faceting, this step is what gives a diamond its inimitable and alluring sparkle. Now, it is important to remember that the value of your diamond will vary significantly in accordance with the quality and execution of the cut. It’s all about the interplay of light and angles, and as you can imagine, creating the precise surfaces and angles on a diamond that will best capture and reflect the light takes immense skill and patience – sometimes the whole process can take up to three weeks. A superbly cut diamond will have a brilliant and elegant sparkle; a cut of lesser quality will shine, well, accordingly.


One of York Jeweller's beautiful engagement featuring pink and white Diamonds

The colour – or colourlessness – of a diamond will dictate its quality and value. When classifying a diamond, a jeweller will judge a diamond against a colour reference chart. The chart, ranging from the letters D to Z, is broken down into five categories: colourless (D), near colourless, faint yellow, very light yellow and light yellow (Z). Essentially, the closer a diamond is to having no colour, the more its value increases. This is due to the fact that clearer diamonds capture and reflect light in a way that yellower diamonds cannot, creating a truly glamorous sparkle and shine. Diamonds of varying colours – known as ‘fancy’ colours – are incredibly rare and exceptionally valuable, and range from yellow, brown, pink, blue, and even black

Fun fact: Black diamonds, called carbonados, are the hardest and strongest form of natural diamond, due to the fact that they contain none of the mantle-born inclusions found in other diamonds, some researchers believe that these beguiling black-beauties were formed in interstellar ​supernovas, some billions of years ago.


The clarity of your diamond is one of the markers of its value.

The vast majority of diamonds contain natural imperfections or ‘fingerprints’ such as fractures, chips or clouds, and these are called inclusions. Most inclusions aren’t visible to the naked eye, but will affect the diamonds ability to refract light. As a rule of thumb, the fewer inclusions in a diamond, the greater the clarity and the higher the value.


Contrary to popular belief, a diamond’s carat is a measure of its weight, not its size. In essence, the heftier the jewel, the bigger the price tag, but this doesn’t necessarily mean that bigger is better. A diamond of modest size, set tastefully in an elegant ring can often look more glamorous than a giant rock, and a row of lovely little princess cuts will forever make a timeless and graceful choice. In the end, it all comes down to the confluence of your personal taste and budget. 

Naturally, buying diamonds can be a daunting task, but now, with a little know-how and a reliable guide, you can relax knowing that you’re well equipped to make an informed and calculated decision, and that your loved ones will receive the quality they deserve.