What Does Carat Size Mean? And Does It Matter?

You may think you know a thing or two about diamonds—the precious stones formed deep in the earth over a billion years ago—but think again. Several factors help decipher the value of these coveted gems, namely the 4 Cs: Cut, colour, clarity and carat.

How to Evaluate Diamonds

Cut

Cut refers to "how well a diamond’s facets interact with light". A well-cut diamond will display "superior brightness, fire and scintillation," according to Beyond 4Cs. Some confuse shapes such as pear, round or cushion with diamond cut. Unlike shape, though, this factor refers to attributes including proportions, symmetry and polish.

Colour

Colour relates, unsurprisingly, to the diamond’s colour. Whilst coloured gems are on a scale of their own, white "diamonds are valued by how closely they approach colourlessness—the less colour, the higher their value," according to the GIA colour scale—the industry standard for diamond grading.

Clarity

Clarity refers to the "qualitative assessment of the flaws present in a diamond" and can be classified into two categories: Blemishes, which appear as chips or scratches on the surface, and inclusions, which are a diamond’s internal flaws. The fewer number of flaws, the greater the value the diamond possesses.

Carat

Carat is arguably the most crucial facet of diamond grading and refers in short to the weight of the diamond. Many may wonder why is it not just called weight? Well, that would be far too easy.

The carat system has a rather interesting and unexpected origin—the humble carob seed. These seeds were considered even in weight, so were used as a weighing reference by gem traders as far back as the 1500s. It has since been proven that carob seeds are quite varied in weight and a highly unreliable reference. According to Blue Nile, “it wasn’t until 1907, at the Fourth General Conference on Weights and Measures, when it was agreed upon that one diamond carat would be equal to 200 mg, or .2 grams, of a diamond."

To complicate matters a little more, each carat is also subdivided into 100 points, giving an even more precise measurement. According to GIA (Gemological Institute of America), "diamond price increases with diamond carat weight because larger diamonds are rarer and more desirable." But bigger isn’t always better as clarity, colour and cut also need to be considered when making an evaluation.

To provide an example of jewels that are a cut, or carat, above the rest, we have rounded up three dazzling diamond rings from Tiffany & Co that truly outshine in every aspect.

Tiffany Soleste Ring

The Tiffany Soleste® collection takes its name from “sol,” the Spanish word for sun. This mesmerising round platinum ring with a brilliant centre diamond with a carat weight of 0.15 is surrounded by smaller round diamonds with a total carat weight of 0.28.

Tiffany Soleste Princess-Cut Halo Engagement Ring

The Tiffany Soleste Princess-cut Halo Engagement Ring includes a stunning princess-cut centre stone with chevron-like waves of facets, a scintillating halo of brilliant bead-set diamonds, complete with a diamond platinum band.

Tiffany True Engagement Ring

The Tiffany True Diamond set in platinum is the most classic engagement ring. The ring, created using ethically sourced diamonds, is available in a variety of carats ranging from 0.62 ($10,300) to 2.48 ($178,000).

Love jewellery? These precious gems are even more valuable than diamonds.