Whether you’re looking for the perfect earrings or just shopping for your jewelry collection, you’ll likely hear the terms carat and karat.
Although they may look and sound similar, carat and karat refer to two very different things. But what do they mean? And what’s the difference?
In this article, we are going to look at the correct spelling, meaning, and usage of two of the most common (and often confused) terms. So that you can better understand jewelry finishes and how they are measured.
When you’re describing jewelry, you typically focus on three specifications: dimensions, weight, and purity. The difference between carat and karat lies in these factors.
Despite popular belief, a carat does not measure the size of a diamond. Gemstones are measured in millimeters based on their diameter. Instead, carat measures the weight of the gemstone. One carat equals 0.20 grams. You will often see carat abbreviated ct or cttw for total carat weight when referencing multiple stones.
Carat size determines the price of your jewelry. The larger the carat size, the more expensive the jewelery. This price can rise significantly as the carat size increases, and the increase isn’t on a linear scale.
Karat instead indicates the purity of gold rather than its weight. It refers to the percentage of gold in an alloy out of 24 parts (e.g. 18K gold is 18/24 gold). The purest form of gold is 24 karats, which is also written as 24K.
While desirable for value, 24K gold is too soft to be used for jewelry, so it’s usually mixed with other metals to form an alloy and enhance its durability and strength. As a result, lower karats are more common, because a piece of jewelry that’s 14k gold will be stronger than one that’s 18k gold.
Until the 15th century, gem traders didn’t have a standard system to weigh their products. This situation created difficulties and confusion, however at that time, the only way to measure something was to link it to another physical object.
The word ‘Carat’ originates from Ceratonia siliqua, commonly known as the Carob tree. Are you surprised? The term carat comes from Medieval Latin carratus, which derives from Arabic qīrāṭ in turn borrowed from Greek kerátion, which means 'carob seed'.
In ancient times, carob beans were a standard for weighing small quantities. They varied very little in weight compared to other species of seeds, and they were effective in a time when technology didn’t make exact weights possible to track.
So the traders commonly used to compare the weight of gemstones to the seed of the carob tree and hence determined the weight. Today with more advanced technology, we know that there is plenty of weight variation between carob seeds, and probably some poor ancient Greeks have had a raw deal!
Karat is a variation of the term carat. While there’s no record of people using carob seeds to measure gold, historians believe that karat has a different spelling but the same origin.
The Greek measure in fact was the equivalent of the Roman siliqua, which was one-twenty-fourth of a golden solidus of Constantine; hence karat took on a sense of "a twenty-fourth part," especially in expressing the fineness of gold when used as jewelry, and thus it became a measure of gold purity.
The carat is the globally recognized unit of measurement for gemstones. However, for years different countries around the world had their own measurements for what one carat would equal. For example, in Cyprus, a carat was 187 milligrams. On the other hand, in Italy, a carat was 216 milligrams.
In the Fourth General Conference on Weights and Measures in 1907 everyone agreed to adopt the carat as the standardized weight measurement for gemstones. Today, no matter what corner of the world you travel to, a carat will weigh the same: 0.20g.
The substitution of karat for carat in regard to precious stones is considered incorrect, whereas the reverse—using carat in place of karat to indicate the pureness or fineness of gold—is considered acceptable in some region.
In the UK and Australia, “carat” is the default often used to refer to gold purity whereas the US tends to use “karat”. However, “karat” is never used to describe diamond weight, no matter where in the world you are.
Now that you know all about carat and karat, what the difference is, and what each one means, you can read jewelry descriptions like a pro and you’ll be sure to find the right jewelry for you at Mantarraya NYC!
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