Diamond Guide

To choose the perfect diamond, you need to know a little about how they are graded. There are four key aspects to consider when selecting a diamond, known as the four Cs, and each affects the gemstone’s look and value.


You should first decide on the diamond’s cut, or shape. The cut is undoubtedly the most important factor when selecting a stone, as this determines the diamond’s “sparkle” and has the most impact on its overall beauty. Our Compose by Clogau® diamonds are available in the classic round brilliant cut, perfected to generate maximum radiance, and the princess cut, a contemporary square cut that has become very popular in recent years.


A diamond is measured by how colourless it is. Diamonds are graded from D (colourless and extremely rare) to Z (noticeably coloured). Compose by Clogau® engagement ring diamonds are near colourless and of superb quality, and our Compose service offers three carefully selected options for you to choose from: D, G and I (D being the best).


The weight of a diamond is measured in carats and points; 100 points = 1 carat. The diamond weight is an indicator of the overall size of the diamond (but not the quality of the stone). The ideal carat weight for an engagement ring will depend on the size of the wearer's finger and your budget.


Almost every diamond contains naturally occurring imperfections. Most of these are too small to be seen with the naked eye and are only visible using specialist magnification equipment. The imperfections have no discernible impact on a diamond’s overall appearance. Diamonds are graded from FL (flawless) to I3 (not recommended). When you start designing your Compose by Clogau ring, you can choose from diamonds rated SI1 (slightly included), VS2 (very slightly included) and VS1 (very slightly included, our best).

If you need any further advice, please don’t hesitate to contact our sales office on 0345 606 88 77 who will be more than happy to advise you further.