The alluring sparkle of a diamond is hard to resist. When looking to choose a diamond yourself, how do you know which diamond to buy? This guide offers advice on how to choose a diamond in terms of the ‘4Cs’: four criteria that define a diamond’s cut, carat weight, colour and clarity, which together determine the diamond’s quality.
A diamond’s shape is the overall outline (geometric shape) that a diamond is cut into. Whilst it’s one of the first and foremost components to choose when deciding on a diamond, this is not to be confused with the 4Cs ‘cut’. Diamond cut is about how the diamond is cut from the source material and how it’s polished, which effects how much its facets absorb and reflect light – hence how much it sparkles. Technical terms for a diamond’s reflection of light are: brightness, fire and scintillation.
Here are the six most common diamond shapes. A point to remember is that a diamonds shape can effect how ‘big’ a stone looks, even at equivalent carat weights. The summaries below explain this.
Founded in 1900, a round cut diamond is the most popular and versatile shape of diamond
Founded in 1960, an oval cut (also known as a modified round brilliant cut diamond) is a popular choice for diamonds and coloured gemstones alike.
Cushion cut diamonds have excellent dispersion (or ‘fire’ as it’s known) that gives those flashes of light for which diamonds are renowned.
The elegant and striking marquise cut is shaped somewhat like a sailing boat with its long, slim oval outline that narrows to points at both ends.
The octagon cut was initially created as a shape to cut the more fragile emerald gemstone but it is now used with diamonds alike; referred to as an emerald cut diamond in these instances.
With its unique and eye-catching teardrop shape, pear cut stones make unusual and impactful pieces of jewellery.
In terms of cut, a jeweller looks at the ‘face-up’ appearance of the diamond (fire and scintillation), how weight is distributed within the diamond, and its symmetry and polish.
Depending on these factors, a diamond’s cut will be graded on a scale of: Excellent, Very Good, Good, Fair or Poor. A Fair or Poorly cut diamond will not have the right proportions, symmetry and polish to reflect light well and will not be desirable. It’s likely to look flat and lack lustre.
A ‘carat’ is the unit of measurement used in the ‘4Cs’ to specify a diamond’s weight. One carat is equivalent to 0.2grams. It’s important to remember carat weight isn’t the same as diamond size. Different shaped diamonds hold their weight differently. Two diamonds of the same carat weight might differ in size if one has a shallower cut and large surface area (therefore appearing ‘bigger’).
Whilst a diamond with a high carat weight sounds impressive, bear in mind the other 4Cs are important to consider. A high carat weighted diamond that scores poorly on the other 4C characteristic won’t have the same impact and sparkle as a lower carat, higher quality diamond.
From left to right the Carat weight and therefore the size increases
Ironically, a diamond’s colour is measured according to how ‘colourless’ it is. Most diamonds have a yellow tint. Those with the least noticeable tint are rarer.
Colourless diamonds are graded from D to H. Those with a slight hint of colour are graded I to M, and below M there is an increasingly yellow tinge to the stone. After Z, diamonds become classed as natural fancy coloured diamonds which are considered exceptional.
D – F
G – H
I+
Choosing diamond clarity is often the last thing to pick. It is based on whether the diamond has any blemishes or inclusions that interrupt the diamond’s transparency, and ultimately its return of light.
Diamonds with the highest degree of clarity are known as ‘flawless’ (FL). A flawless diamond will have enhanced sparkle. After Flawless, a diamond’s clarity is defined as ‘Internally Flawless’ (IF), followed by ‘Very, Very Slightly Included’ (Vvs1 and Vvs2), then ‘Very Slightly Included (Vs1 and Vs2)’ through to ‘Slightly Included’ (Si1 and Si2) and Imperfect diamonds (I1, I2 and I3). Diamonds with a lower the clarity grade will appear cloudy.
It’s important to note that minor inclusions shouldn’t be seen as ‘damage’ – they add character and are the diamond’s unique fingerprint.
VVS+ Clarity
Vs1 & Vs2
Clarity
Si1 & Si2
Clarity
All gemstones that are used by Veale Fine Jewellery are ethically sourced from a trusted, longstanding supplier who guarantees non-conflict diamonds that are fully covered by the Kimberly Process. The Kimberly Process prevents conflict or ‘blood’ diamonds, that are illegally traded to fund wars, from entering the jewellery supply chain.
Colour and clarity are the features people struggle most with. They can be overlooked but their impact has a big difference. When weighing up which quality indicator is most important to consider between two stones, it’s worth remembering that colour is viewed by the naked eye, whereas clarity is viewed under x10 magnification. So a stone’s colour would probably make a greater difference to the overall desirability of a stone than small variation in clarity would.
Diamond certification ensures an unbiased assessment of a stone’s quality. It’s important that diamonds, particularly those above 0.5 carats, are certified by an independent and recognised certification body. GIA, HRD, IGI and EGL are the leading certification bodies in the diamond industry, with GIA being the most stringent.
If you are looking to get the most ethically sourced natural diamond that you can, diamonds that are stamped with the Canadian stamp fall into this category.
A diamond can be shaped in different styles that are tailored to the spirit of the jewellery that is being created
The shape of the diamond will also determine the setting that is best suited to showcase and protect the stone(s).
