Po-tay-to, po-tah-to, to-may-to, to-mah-to.
What is a carat? What is a karat?
When you’re purchasing jewelry and you start discussing carats and karats, it’s important that you understand the difference and here’s the down ‘n dirty for you (if your jewelry is dirty, click here for jewelry cleaning tips):
Basically, a carat is a unit of weight whereas a karat (as with gold) is a unit of purity.
A carat is a unit of weight that equals 200 milligrams and is most commonly associated with gemstones, especially diamonds and other precious gems. To put it in perspective, a pound equals 453 grams. That’s a heckuva gem…especially when you consider that the largest cut colorless diamond in the world weighs 530 carats.
That diamond is the Star of Africa I (also called Cullinan I) and was found 18 feet below the earth’s surface in January of 1905. The stone was presented to King Edward VII of Britain for his birthday.
The carat has nothing to do with the color or clarity of a stone, however beautiful. The carat is all about the weight of the stone. This is particularly interesting when you change the “c” to a “k”…
Similar to “krab” (the “crab” meat that you can buy that is typically puverized surimi white fish), a karat with a “k” is a unit of purity most commonly used with gold. This dates back nearly a thousand years to the German gold coin referred to as a mark, which weighed 24 carats itself. The purity of the gold in the coin (karats) was expressed in the amount of gold (carats/weight) that was present in the coin itself, which weighed 24 carats.
24 karat gold is pure gold, but you won’t find yourself choosing from a selection of 24k gold anytime soon because it’s just too soft. The reason you find different karats of gold jewelry is because to make a piece that is wearable by you or your significant other or anyone else, the gold must be combined with other harder metals to make the jewelry stronger and more durable.
Gold is typically mixed with copper or silver in this way. Given that 24 karats indicates pure gold, think of each karat as 1/24th of the purity of the final product. For instance, if you buy a piece of jewelry that is 18k gold, the final product is 18 parts gold mixed with 6 parts copper. The lower the karats of gold, the more copper or silver in the mix.
The bottom line: carats are a measurement of gemstone weight and karats are a measure of the purity of the gold in the setting itself.