First, a geology lesson: Diamonds are the hardest naturally occurring substance known to man and are formed beneath the Earth’s surface when crystals of diamond occur in volcano feed-pipes. When volcanoes erode down, they release diamonds from their feed-pipes into layers of gravel which are later mined. However, due to the relative rarity of this natural process, diamond mines are found in just a handful of sites around the world. In rough form, diamonds are shipped to the world’s cutting centres to be shaped and polished before being set as jewellery. It is the hardness, brilliance and sparkle that emerges during this process that transforms them in what you see today
Now for a quick history lesson, legend dictates that in 1477, Archduke Maximilian of Austria give Mary of Burgundy a diamond ring to celebrate their imminent engagement? He placed it on the third finger of her left hand – the finger believed by ancient Egyptians to have a vein that led straight to the heart.

The Four Cs

So now that you a brief insight to the history and geology of a diamond, you can familiarise yourself with the “Four Cs” – cut, colour, clarity and carat. All must be considered equally when comparing diamonds.


This is not to be confused with “shape” as is so often the case, the cut of the diamond is not influenced by nature and is very important as this dictates how light enters and exits the diamond. Cut a diamond incorrectly and the defining sparkle will be compromised. There are tiny planes cut on the surface of a diamond which are called facets, each angled and sized so that light can reflect and exit the diamond, an effect known as its “fire”. Make the cuts too deep or too shallow and the diamond will be less brilliant.


The most valuable and rare colour is white, that is to say, colourless. Jewellers grade absolutely colourless diamonds with a “D”. The scale moves down to “Z” which is a light yellow, whereas a “G” colour diamond is classed as an ideal colour due to its near colourless.


Most diamonds contain tiny natural marks called inclusions also known as “nature’s fingerprints”. The number of inclusions, their size and location all affect a diamond’s clarity grade. They can look like small clouds or feathers and can be visible to the naked eye. Inclusions can affect the diamond’s fire, but they also make your diamond unique and shouldn’t always be seen as a fault. The best and most expensive is IF or internally flawless,


The weight, and thus the size, of a diamond is measured by carat. A carat is divided into 100 smaller units called points. For example, three-quarters of a carat is 75 points.