The four Cs of diamond grading, Dublin

Diamonds are forever, as the saying goes. They are also expensive!

To help the man on the street understand how diamonds are priced, Dublin jewellers refer to the four Cs of diamond grading. These are four parameters that subjectively grade and quantify diamond quality.

The four Cs are : Colour, Cut, Clarity, and Carat.

Colour: The colour scale is an alphabetical scale that runs from D to Z. D is the highest grade, and refers to a totally colourless diamond. Z colour diamonds would be noticeably yellow or brown.

Clarity: The clarity scale runs from Flawless to Included. Clarity grading is done with a jeweller's loupe, a hand held magnifying glass with 10x power. The scale is Flawless, Internally flawless, Very Very slightly included grade 1 and 2, Very slightly included grade 1 and 2, Slightly included grade 1 and 2, and Included grade 1, 2 and 3. In general it is important to check that the inclusions are invisible to the naked eye.

Cut: This refers to the shape of the diamond, and also to how well the diamond has been proportioned. The cut grade scale runs from Excellent to Poor. There will be a noticeable increase in brightness and sparkle between an excellent cut and a poor cut.

Carat: this is a measurement of weight, and does not relate to the quality of the diamond. One carat is 0.2 grams. In general is it advisable to have a smaller diamond of higher quality, than a larger, lesser diamond.

The secret to choosing a nice diamond ring in Dublin is more than simply looking at the quality grades. It is a matter of finding a piece of jewellery that you love and are happy to wear forever. Particularly with diamond cut, which can be very much a matter of beauty being in the eye of the beholder. I have often seen cushion cuts and irregular cuts with great Art and beauty, which might not grade as technically perfect. This is because the cut grade system only applies to round brilliant cut diamonds, so it is misleading to apply it to a vintage cut diamond.