Common percentages of gold purity
Gold jewelry is measured by its purity, or how much actual gold is in the piece. This amount is usually stamped on the jewelry, the most common of which are:
10k or 417 = 41.7% of pure gold
14k or 585 = 58.5% of pure gold
18k or 750 = 75% of pure gold
24k or 999 = 100% of pure gold
These karats apply to any color of gold - for example: 14k yellow and 14k rose gold will have the same percentage of gold, 58.5%. For more information on the colors of gold, check out our blog post.
What exactly is gold purity?
Gold in its natural state is soft and malleable so it’s often alloyed with other metals to increase its strength. Although the percentage of precious metal present in jewelry can be any number, just a select few standards are commonly used. All gold jewelry should carry a stamp indicating the purity of the gold, stating how much gold is in the piece. A Karat stamp (10k, 14k, and so on) is an American standard, while a Three-Digit Stamp (417, 585, etc ...) is a European standard. They look different, but they both mean the same thing.
Where did the word Karat come from?
The origin of the words Karat and Carat have a delicious history, they come from “carob”, the same tree that gives us chocolate. Hundreds of years ago, a single seed from the carob tree was used as a standard for weight against a small gemstone. This unit of measurement eventually became the standard for measuring the purity of gold as well. Over time the different spellings were created to differentiate between the two, with Karat ("k" or "kt" for short) being the measure of gold purity and Carat (“ct” for short) being the measure of a gem's weight.