What does the Carat of a Diamond Engagement Ring Mean?

The ‘carat’ of a diamond engagement ring is generally regarded as the one of the important 4Cs when it comes to valuing diamonds. Many assume that a carat, taken from the ‘carob’ seeds which were the original unit of measure for diamond traders, is an indication of size, but it is actually a unit of weight. Today, one carat equals approximately 0.2 grams. It is also worth mentioning another point of confusion regarding the word ‘karat’, which is completely unrelated to diamonds and is used to describe the purity of gold.

Carat weight is seen as the most significant factor when it comes to determining the price of a diamond engagement ring. As you might expect, the bigger the diamond, the higher the price. However, it is not a simple matter of a two carat diamond being twice as expensive as a one carat diamond; rather, the price of a diamond rises exponentially, as opposed to linearly, with size. This is the result of the rarity of larger diamonds, as Mother Nature gives us far more small diamonds than larger ones, and fewer than one in a million rough stones mined are large enough to be cut and polished into a one carat diamond. As a result, you will typically pay not only more in total as the carat weight increases, but on a price-per-carat basis as well.

When it comes to choosing a diamond engagement ring, you should also bear in mind that diamond measurements will vary. The average one carat round diamond will measure around 6.5 millimetres in diameter. Two diamonds with an equal carat weight can appear very different in size as a result of the cut. For instance, a one carat marquise will tend to appear larger than a one carat round. Two diamonds of equal carat weight can also have very different costs, not only as the result of the cut, but also of colour and clarity.

Couples should not only consider the budget when it comes to picking out the perfect diamond engagement ring; it is a common assumption that every woman wants the largest and best diamond that her partner can afford. However, women have differing tastes and lifestyles which can all have an impact on their individual preferences. For instance, some women may not be comfortable with something large and flashy, because it doesn’t suit their character or it isn’t practical if they’re very active, as larger stones have a greater tendency to catch on things. Otherwise, it comes down to a balance between size and quality and ultimately determining what characteristics are most important to you and your partner.

Frederick Holm writes for the F&L Designer Guides, which hosts a thriving community of independent engagement ring designers in the UK. Inspired by their journey of discovery in search of a distinctive, one-of-a-kind diamond engagement ring, F&L now celebrates the works of their favourite designers and helps promote the notion of "Go Bespoke" as a more imaginative and interesting alternative to the limitations of High Street shopping.

Writer and Online Marketing Manager in London.