Understanding The '4C's' of Diamonds

Understanding the '4C’s' will help you navigate the “diamond maze” and enable you to make an informed and confident decision that suits your ideal budget and design. Discover the four C's below;


Out of the 4C’s, the cut might just be the most complex. Not to get confused with the overall shape of diamond (round, pear, oval etc), but the quality of the facets and how well these facets interact with the light. Diamond cuts are graded in 5 levels: Excellent, Very Good, Good, Fair, Poor. 

The exact proportions that will yield the best visual effects for each shape diamond and give the diamond a rating of ‘Excellent’ has been refined over the years. We now know the exact proportions that will produce the highest level of brightness (internal and external white light), fire (the scattering of white light into all the colours of the rainbow), and scintillation (the amount of sparkle a diamond produces and the pattern of light and dark areas caused by reflections within the diamond).

The other elements that play a key role are the weight relative to diameter, girdle thickness, symmetry of the facets and the quality of the polish.  What this means is that investing in a high level of craftsmanship will bring out the best of the diamond you choose. The cut plays a significant role in the diamonds final “sparkle” and value. 


Clarity refers to the size, nature, location and number of imperfections in a diamond. These can be internal inclusions or external blemishes. The fewer inclusions on a diamond, the rarer and more valuable the diamond will be. We grade the clarity of diamonds into 11 specific grades viewed at 10x magnification, these are:

  • Flawless (FL) – no inclusions or blemishes visible 
  • Internally Flawless (IF) – no inclusions visible
  • Very, Very Slightly Included (VVS1 and VVS2) – Inclusions are present but are very difficult to see even with a trained eye
  • Very Slightly Included (VS1 and VS2) – Inclusions are present, but are minor
  • Slightly Included (SI1) – Inclusions are noticeable only with the assistance of magnification
  • Included (SI2, I1, I2, and I3) – Inclusions are easily seen under magnification and can be seen with the naked eye 

The diamonds that we source at She Fine Jewellery are strictly SI1 and above.  It isn’t always guaranteed that diamonds graded as SI1 will be eye clean as different gemological institutes do grade slightly differently, so it is definitely a good idea to view diamonds in person or remotely via 10x magnification video. 


    Diamonds are graded based on the absence of colour, with the highest grade being ‘D’ (colourless) through to  ‘Z’ (light yellow). Where is A, B, C you might ask? Well let’s just say the grades A, B, C were once used, but loosely used, and GIA (the leaders in diamond grading) wanted to start fresh!

    Colours D-F are classed as colourless and the rarest and most finest. Colours G-J are near colourless, and colours K onwards are classed as slightly tinted. These colour grades include different colour shades such as champagne, cognac and even grey. 

    Many of the colour distinctions are very subtle to the untrained eye and we don’t walk around comparing diamonds side-by-side. However, to guarantee a high quality and bright white diamond we at She Fine Jewellery source D, E and F grades. 

    We can and do source G colour diamonds that have a high cut and clarity grade, as the other contributing factors do increase the overall appearance of the diamond and typically they can well-priced.




    The carat of diamond is the measurement in weight, with one carat equaling 200 milligrams. Carat is probably the most talked about of the four C’s as typically people want big! But as you now know, bigger doesn’t always mean better. If all other factors remain equal, then sure! Bigger is better, and with that comes a higher price as larger diamonds are rarer and highly sought after. 

    I have intentionally left this to the end of the article as I’m sure by now you can agree that the other diamond characteristics come first. So invest your money in the previous C’s and you will get the biggest bang (sparkle) for buck! 


    The fluorescence of a diamond is commonly forgotten about or not discussed when purchasing a diamond, even though 25% to 35% of diamonds submitted to GIA for grading over the past decade exhibit some level of fluorescence.
    Fluorescence is graded in 5 levels: None, Faint, Medium, Strong, Very Strong.
    A stone that exhibits fluorescence emits a visible glow when exposed to ultraviolet rays. Why does this come into the buying equation? Well, diamonds with fluorescence can appear cloudy, hazy or oily in daylight. So if you have invested in a beautiful D colour diamond, you are going to want that rock to sparkle in the sun! This is why at She Fine Jewellery we suggest only using diamonds with no fluorescence.