Gold plating is the process of adding a thin layer of gold to another metal in order to give that metal a gold-like appearance. In most cases, the layer of gold is very thin, just enough to cover all exposed surfaces of the other metal. It is commonly used in decorations and in jewelry plating.
The benefit of gold plating for jewelry is that it gives the look of gold, but does not have the cost of gold. In jewelry applications, gold plating is most commonly applied to silver. Thus, the jewelry actually includes two precious metals, rather than just one.
While many may commonly associate gold plating with jewelry, it is not the only application for the practice. Gold plating is also commonly associated with electronic applications. This is done to allow better conductivity and make things resistant to abrasion and wear, along with other benefits.
Gold plating can be accomplished in a number of different ways, including electroplating. This is done by putting the object being plated, the cathode, into a solution, usually water. It is connected to the negative side of a charge, such as a battery. Then, the donor for the plating, the anode, is also placed in the solution connected to the positive side of the charge. Ionization occurs and the anode slowly dissolves, with the positively-charged ions in the metal going to the negatively charged product.
However, gold plating, like most types of metal finishing, can be done in a number of other ways. The gold metal can be suspended in a solution, which is then brushed on the object being plated. The goal is to maximize the effect but to minimize the amount of gold needed to do the job. This is a very low-tech solution that may be used by those doing small jobs privately.
Due to the fact that gold is such a soft metal and the layer over jewelry products is so thin, there will likely be a time when the gold plating becomes worn in spots. Jewelry, especially those pieces worn daily, tends to take a substantial amount of abuse. Taking such items to a jewelry repair shop is the best way to restore them to their original luster. This type of repair is usually very inexpensive and may even be included in some service policies.