Previously, we’ve talked about the difference between “carat” (a unit of weight for gemstones) and “karat” (the measurement of the purity of gold). If you remember, 24-karat gold is pure gold, or as close to pure as possible. Gold jewelry advertised as “24 karat gold” is at least 99.99% pure gold. 18-karat gold, on the other hand, is made of 75% gold and 25% other metals, typically copper or silver.
You may have noticed that we use 18k gold in our jewelry. If karat is a measure of purity, wouldn’t you want the purest gold available? Shouldn’t luxury jewelry be made with only the purest gold around?
Not exactly. The answer has to do with the chemical properties of gold itself. Part of the reason gold is valuable is that it was useless for much of history. Today, of course, gold is used as a conductor in electronic devices, but you can’t forge a sturdy shovel or sharp knife with gold. It’s just too soft for that purpose. But for all its uselessness in toolmaking, it is rare and pretty, so we started making pretty things out of it, things that had spiritual or social significance.
We also found a use for it as a measure of value, as in the case of gold bars and coins. Gold bars are always 24k gold. Gold coins, however, especially those minted by governments as currency, are often 22k gold (91.7% gold), which gives you a high level of purity associated with high value as well as a little added durability. You don’t want those coins getting bent out of shape or worn out.
Is 18 Karat Gold Better for Jewelry?
So if 24k gold is so valuable, why don’t we use it in our jewelry? For one thing, pure gold would be prohibitively expensive. The other reason goes back to gold’s malleability. It is a soft metal—so soft that a piece of pure gold can be worked into different shapes by hand. This is why we have the cliché of gold medal winners biting into their medals: pure gold is soft enough that if you bite it, you’ll leave tooth marks. (Unfortunately for these athletes, and their dentists, Olympic gold medals are 92.5% silver and only gold-plated.)
This means that a 24k gold earring can be irreparably bent out of shape while putting it on and a 24k gold ring can be easily damaged by banging your hand into something. Because it is a soft metal, it can also be easily scratched. It is surprisingly easy to accidentally ruin a 24k gold piece of jewelry.
Furthermore, and this is a matter of personal taste, many people prefer the more muted, elegant hue of 18k gold to the bright yellow of 24k gold. For us, 18k gold strikes the perfect balance between the high value of 24k gold and the durability of 14k gold, with a color that looks great with just about any gemstone.
