The 4 C’s

How To Choose A Diamond

The quality of a diamond is broken down into 4 areas: Colour, Clarity, Cut and Carat. Known as the 4 C’s, this trusted grading system (created by the gemological Institute of America GIA) is a global grading system measuring the caliber of the diamond.
fine jewels 4cs colour


The colour of a diamond is graded on a scale from D (Completely colourless) – Z (Light yellow). Most of these colour variations are impossible to see with an untrained eye but do have an impact on price. Chemically pure and structurally perfect diamonds will be completely colourless (D). These diamonds are considered to be the highest grade, and therefore the most expensive. A diamond with a natural colour beyond this range is considered to be a fancy coloured diamond. Fancy diamonds can have tones of yellow, brown, red, green and blue. Those with a darker hue are considered to be extremely rare and have a higher value.


Clarity, which looks at the purity of the diamond, is determined by the presence, size and location of natural flaws or inclusions inside each stone when it is under 10x magnification. Small imperfections can occur due to the nature of how a diamond is created within the earths’ core when carbon is exposed to extreme heat and pressure. These are usually unseen to the naked eye and do not affect the structure of beauty of the stone. These imperfections are graded using the scale below, but it is worth noting that even an SI diamond can only be seen under 10x magnification.
Flawless (FL) No inclusions or blemishes
Internally Flawless No inclusions
Very, Very Slightly Included (VVS1 and VVS2) Inclusions so slight they are difficult to see
Very Slightly Included (VS1 and VS2) Minor inclusions visible
Slightly Included (SI1 and SI2) Inclusions noticeable
Included (I1, I2 and I3) Inclusions are obvious which may affect transparency and brilliance


The cut of a diamond refers to how well the facets of the stone interact with light to display visual effects such as; Brightness, Fire and Scintillation to create that sparkle we know is only possible from a diamond. Cut can often be confused with the shape of the diamond. Chemically pure and structurally perfect diamonds will be completely colourless (D). These diamonds are considered to be the highest grade, and therefore the most expensive. Each diamond is accessed on well it interacts in these areas: Brightness: Internal and external white light reflected from the diamond. Fire: The scattering of white light into all colours of the rainbow. Scintillation: The amount of sparkle a diamond produces and the pattern of light and dark areas caused by reflections within the diamond.


A carat (ct.) is the measurement of a diamond’s weight. 1 carat is equal to 200 milligrams (0.2mg). Each carat is divided into 100 points to allow for more accurate measuring. Sometimes jewellers may use the points alone to describe the weight of a diamond, so you may hear the term ‘seventy-five pointer’ which refers to a diamond with a weight of 0.75ct. Diamonds that weigh over 1 carat will be described in carats and decimals such as ‘one point seven five carats’. You cannot determine the value of a diamond with its carat weight alone without considering the other 3 factors; Colour, Clarity and Cut.

Client Testimonials

What they say

I have a four carat Victorian ring which I purchased a few years ago. It’s always been my dream to own a large solitaire diamond, I was elated with the ring Peter sourced for me as I was very specific about what I wanted. The stone is high quality and was certified by the GIA. I was also given a valuation certificate for insurance purposes. The ring was excellent value and the service I received was exemplary. I still use this company to check the setting every couple of years as I trust them completely. I also part exchanged a smaller ring for a very good price. I wouldn’t hesitate to buy from Peter again in the future

Bev / Customer

Peter found me the perfect engagement ring. Great friendly service.
He was really knowledgeable and made a big decision easy

James / Customer

"I can’t recommend them enough. I needed help and advice when choosing an engagement ring and was delighted with the service. The diamonds they sourced were perfect and bought at a very fair price. I certainly won’t be shopping anywhere else for the future purchases."

Pete / Customer