Understanding Cut

How much light does your diamond reflect? This will depend primarily on the cut grade you select. One of the four Cs – cut, colour, carat and clarity – your diamond’s cut grade is arguably the most important factor influencing its natural beauty.

Not to be confused with shape, a diamond’s cut refers to the depth proportion responsible for light reflection and luminosity. A shallow cut grade causes light to escape through the bottom, while a deep cut misdirects light through the side. Ideally, you want your diamond cut to reflect the same amount of light through the top as it absorbs. As a result, optimal light reflection creates a glowing and radiant shimmer.

Today’s diamond cutters contemplate a diamond crystal’s size and shape, selecting a cut that minimizes waste and delivers the most favourable light reflection possible. Highly trained professional graders then evaluate and rank a diamond’s cut using industry standard guidelines that take several different factors into consideration including a diamond’s diameter, crown, culet, table and pavilion.

Cut grades range from poor, i.e. too deep or too shallow to reflect light back through the top, to ideal/excellent, i.e. the rarest three percent able to reflect all light in precisely the same direction in which it was absorbed. Because a diamond’s cut grade so strongly impacts its brilliance, most gemmologists believe this is the single most important characteristic shoppers should consider when selecting their stone. It is advisable that diamond shoppers choose the highest cut grade possible within their budget.