Sometime during the 3rd century B.C., Archimedes was tasked with determining whether his king’s crown was gold or some other metal. Nearly 2300 years later, we come across the same question here at Condesa. Nowadays we determine an objects metal content using x-ray fluorescence technology. Not all that glitters is gold!
In fact, there are numerous ways in which jewelry can have the appearance of gold. Let us start with a refresher on what constitutes “genuine” gold jewelry. Or what we refer to as karat gold. Broadly speaking, karat gold is any jewelry. Regardless of its color, which has a gold content of 37.5 % (9k) or higher.
The rest of the metal content is usually a mix of silver, copper, zinc, nickel, or palladium. These are in varying combinations & proportions, but the determining factor is the percentage of gold. Karat gold jewelry should be stamped, where possible, with a number followed by the letter “k”. An example of this is 18k or the actual percentage of gold content, in this case 750. Of course, there are other kinds of gold-colored jewelry too!
One popular technique is Gold Plating. In this process, a lesser metal, usually brass or silver, is placed in a solution containing free gold ions. Direct electric current is applied to the item. This allows the gold from the solution to galvanize onto the piece, creating a micro thin layer. The durability of the plating depends on the thickness of the gold deposit layer. It allows depends on how much rubbing the plated piece receives when it is worn.
At a commercial level, it is nearly impossible to know how much gold has been plated onto a piece. Sometimes even the identity of the base material used is unknown. The exception to this is jewelry that is sold as “Vermeil”. An internationally accepted trade term. Denoting silver jewelry with at least 2.5 microns of gold plating.
But then there is also gold-filled jewelry!
Another widespread technique is the use of “Gold Filling”. Prevalent in chain manufacturing, this is where a tube of gold is wrapped around a base metal rod. After that, it is drawn into thin wire, which is used to manufacture the chain. Quality hallmarks on such chains usually say GF 14k, GF 10k or sometimes 1/10 GF or 1/20 14k. Gold filled chains will stay gold colored for a long time.
Finally, we often get asked about “Fool’s Gold”. Once extracted from the ground, iron pyrite is not gold colored enough to fool anyone! Curiously though, it is used quite often in jewelry. When it is fashioned into faceted stones, commonly known as marcasite. Technically speaking, if the metal content is disclosed by the seller, gold colored jewelry can be a valid & less expensive alternative to karat gold. At Condesa, we routinely manufacture custom pieces in karat gold of all qualities & colors as well as vermeil.