Pure gold is too soft to use for most items, especially jewelry which receives a lot of wear and tear. So, it is often combined with other metals, such as copper, to give it added strength. Pure gold is called 24kt, while most gold jewelry is in either 18kt, 14kt, or 10kt gold. If you have a gold chain that is considered 18kt gold, then this means the gold is 18 parts gold and six part of another metal. The melting point of gold ranges from 1380 degrees F to 2732 degrees F.
Jewelers like working with gold because, though it is a heavy metal, it is easy to form. There also isn’t much to polishing this metal because it does not oxidize. Usually a quick rub with a polishing cloth is all that is necessary.
Often jewelry is also gold-filled or gold-plated. Gold-filled is a gold plating that is either soldered, brazed, or welded onto another metal. To be considered gold-filled, a plating must constitute at least 1/20th of the metal in the article. Gold-plated or overlay, also called vermeil, is most often 10kt or 14kt gold bonded onto either sterling silver or a base metal. This overlay only needs to be about 120 micro inches of gold over the metal.
