Gold 14k (with 58% content of gold) is very much a US specificity, while in Europe the standard in jewelry has always been 18k (75% of pure gold).
But why 14k gold is a US specificity ?
Historically, 14k jewelry has always been strong in the USA for 3 reasons :
- The distribution of jewelry in the USA has always been very much concentrated, and still today few companies own the majority of unbranded jewelry stores in the country. Jewelry brands were originally not so common and these brands owned few shops compare to unbranded jewelry companies. These distribution companies were the market leaders and they understood that they could sell to more people with cheaper products, that is with a lower gold grade, and most importantly that they could make better margins. Therefore they asked the manufacturers to produce mainly 14k gold. That's how the 18k jewelry was dedicated to the richest people, and the 14k with a much bigger volume was dedicated to the middle class. In Europe, legal requirements originally fixed the grade to 18k and it was then widely adopted as a standard even when others grades were officially recognized.
- There is a belief that 14k gold is harder and will resist more to scratches than 18k gold, and ultimately will last more. Actually, the 14k alloy itself is only 10% harder than its 18k counterpart when it goes out of the foundry, but you don't wear a piece of alloy, you wear a piece of jewelry that has been produced through a manufacturing process. And it is is this manufacturing process that will define the specifications of a piece of jewelry. A 18k ring for instance, produced in a tube will be harder than a 14k ring produced with casting, because the process based on a tube will go through several thermodynamic steps that will progressively strengthen the surface of the 18k tube and of the 18k ring. So it is not true to say that 14k is harder than 18k, it all depends on the production process. At Zeva for instance, all our rings are produced through precise machining in solid 18k tubes after different thermodynamic steps.
- Last reason is that there is another belief that 14k gold is more resistant to tarnishing than 18k gold. Tarnishing is caused by external attacks like pollution, chemicals in cosmetics, houshold products, etc... These external elements are going to chemically interact with the metals of the alloys. Tarnishing is a kind of oxydation. The higher the purity of gold in the piece of jewelry, the less it will oxydise. A ring made of pure gold (24k) will not oxydise or very slowly. Therefore a ring in 18k will not tarnish as fast as a 14k piece of jewelry, contrary to rumors heard on the street.
Please also note that the quality of the alloys is also very important when it comes to tarnishing. Some jewelry companies cast alloys using old jewelry with lot of impurities included, or using gold from unknown origin that has not been refined correctly before. Refining is the chemical operation to remove all impurities from gold, so it can be included without risk in a new alloy batch to produce fresh jewelry.
Last but not least, one very important consideration when it comes to choose between 14k and 18k, is the investment value. First of all, 18k gold with 75% of gold retains its long term value much better than 14k because of the higher content of gold. And secondly most of 18k jewelry is branded compare to 14k which is most of the time generic and unbranded. Only branded jewelry keeps its value on the long term. It's a terrible mistake actually to make a gift to someone with an 9k - 14k unbranded jewelry because the value is going to fall very quickly.
It is also important to note that 14k alloy includes some zinc or nickel. Zinc vapors are toxic for the people working in the foundry, so it's a sensible topic, and 14k also includes nickel which is well known to cause strong allergy. It's forbidden in several countries now.
To conclude, 18k gold is the real long term investment value for your jewelry, with a better quality standard than 14k jewelry. It's the ideal quality to pass on to future generations.
At Zeva we produce our 18k alloys with new refined gold to guarantee not only the 18k grade but also the lack of impurities that would otherwise appear sooner or later in your piece of jewelry if not correctly casted. And most of our products (except pendants hand made) are precisely produced with CNC machining with thermodynamic process that guarantee the quality and strength of our products.