If you are choosing a diamond to have your engagement ring, wedding ring or eternity ring custom-made in vintage style, there is much to consider before making your choice.

Our expert staff, led by Rita Brennan – who has a qualification in diamond grading from the renowned Gemmological Institute of America – will help you through the process. They will explain how choosing a diamond involves learning about and considering the four C’s of diamonds – Cut, Colour, Clarity, and Carat. These determine a diamond’s quality and beauty, and hence its value.

  • Cut

    The cut is considered the most important of the four C’s, as this is what the brilliance, or sheer sparkle, of the diamond will depend upon.

    It is the only one of the four C’s that is man-made, as a master diamond cutter will intensely study a rough diamond until finding the best possible way to cut it.

    In a well-cut diamond, light is reflected off two sides for maximum sparkle, and also to allow it disperse somewhat into its spectral components, generating a hint of fire as it does so.

    Guide to Choosing a Diamond - Sample Diamond Cut Types

    There are several international standards for grading the cut of a diamond, all on a variation of a simple order of Excellent – Very Good – Good – Medium – Fair – Poor. Unfortunately, the grading systems are not uniform, so what ranks as ‘excellent’ on one may rank only as ‘very good’ on another. In general though, we recommend choosing a diamond of grade ‘good’ or better.

  • Clarity

    The clarity of a diamond is a measure of its purity, determined by the extent of tiny impurities or blemishes on its surface or within it. These impurities are known as ‘inclusions’ and are perfectly natural due to how diamonds have formed within the earth over millions of years. Diamonds usually grow faster than the other crystals and minerals around them, so tiny trace elements of those other materials become embedded in them.

    Finding a perfectly flawless diamond is exceedingly rare. However, the vast majority of inclusions within diamonds are invisible to the naked eye, and so much so that 10x magnification is employed when determining a clarity grade.

    Guide to Choosing a Diamond - Diamond Clarity Chart

    After ‘Flawless’ (no inclusions whatsoever) and ‘Internally Flawless’ (no inclusions visible within the diamond under 10x magnification) comes the grades VVS1 and VVS 2. The terms stand for ‘Very Very Slight’ inclusions, which are still difficult for even an expert grader to see when magnified to ten times their size.

    Next is VS1 and VS2, meaning ‘Very Slight’. A diamond grader will easily see these under 10x magnification but other people will not, and all VS1 and VS2 inclusions remain invisible to the naked eye.

    The next grades are SI1 and SI2, meaning ‘Slightly Included’. These can easily be seen by all under 10x magnification, but still cannot be seen with a microscope.

    After that are I1, I2 and I3, meaning ‘Included’. These inclusions are visible to the naked eye and those in an I3 grade will be quite noticeable, as they will drastically affect the overall appearance and sheen of the diamond.

    Overall, diamonds graded VS1, VS2, SI1 and SI2 represent the best choices for most people. Their inclusions cannot be seen by the naked eye and they come at much more affordable prices than diamonds of higher clarity grades.

  • Colour

    Referring to the ‘colour’ of a diamond is actually something of a misnomer, as it is actually a lack of colour in a diamond that is most sought after and expensive.

    A diamond’s colour grade is denoted by a letter between D and Z, according to a scale formulated by the Gemmological Institute of America (GIA). D is completely colourless, while E and F are also considered colourless. G to J are ‘Near Colourless’; K to M are ‘Faint Yellow’; N to R are ‘Very Light Yellow’, and S through to Z are ‘Light Yellow’.

    Guide to Choosing a Diamond - Diamond Colour Grading Scale

    While most people seek as colourless a diamond as possible (i.e. D, E, or F), a diamond that is rated down as far as J will suit a yellow gold band, as the yellow of the gold will be more sympathetic to the slight yellow hint of the diamond.

  • Carat

    The final ‘C’ is carat, which is simply a measure of the weight of a diamond – not its size or purity or anything else.

    A carat weighs 0.2 grams, and each carat is further divided into 100 points.

    Diamonds of gem quality become rarer in nature the heavier they become, and because of this rarity, the price increases accordingly. For instance, the price of a one carat diamond will be more than twice the price of a 0.5 carat diamond (assuming the other three C’s – cut, clarity, and colour – are the same).

    Guide to Choosing a Diamond - Diamond Carat Size Guide

    A correctly-proportioned diamond of a certain carat weight should be of a certain size. For example, a one carat diamond should measure approximately 6.5 mm from side to side. Some diamonds are cut to different proportions to make them appear larger or to retain extra carat weight, but these will not sparkle as much as a properly-proportioned diamond.

Choosing a diamond for a precious piece of jewellery you will wear every day for the rest of your life is a big decision. We are here to help every step of the way and we will offer expert individual advice tailored to your own personal tastes and budget.

Just call in to our shop at 24 Patrick Street in Kilkenny during opening hours or call us to arrange an individual appointment.

About Lorimat Jewellers

Lorimat Jewellers are leading suppliers in the South East of Ireland of engagement rings, wedding rings, and eternity rings of vintage design and style. We offer modern interpretations of timeless classics, and for decades, we have helped couples to show their love in the greatest way possible by helping choose the perfect rings for them.