A stamp reading 18KGP means that the jewelry is gold plated, so an 18KGP white gold item would be plated with 18 karat white gold. The metal underneath the gold is usually copper or silver, but these can diffuse into the gold and tarnish the color.Know More
Copper has a nickel-plated layer before adding the gold, while silver metals usually have layers of copper and then nickel. The nickel is a barrier metal that can help stop the primary metal from ruining the finish of the gold. If the barrier metal is not used, it can take only a few months to a few years before the gold is tarnished.
Karat is a term used to describe the purity of the metal and 18 karat gold is gold mixed with other metals, making it 75 percent pure. Each karat represents 1/24th of the gold's purity, or 4.1667 percent. Twenty-four karat gold is the purest, and 12 karat gold is 50 percent pure. Gold jewelry is usually sold at between 9 and 18 karat, and in the U.S. the minimum value for gold is 10. Gold is mixed with other metals in jewelry because gold as a metal can be damaged easily. Twenty-four karat gold is usually reserved for ceremonial or display use.Learn more about Precious Metals & Gems
M & M Gold Exchange notes that jewelers and others have long used the same tests, including applying nitric acid and attempting to attach a magnet to a metal piece, to verify an item is made of real gold. In the United States, anything less than 10 karats is not considered real gold.Full Answer >
Aside from never using the item, it is nearly impossible to prevent some white gold pieces from turning yellow. This is particularly true for jewelry. White gold jewelry, especially rings, has a tendency to gradually turn yellow due to natural erosion caused by friction and normal wear and tear.Full Answer >
Gold overlay is a thick coating of gold that jewelers lay over metal jewelry. The process has been around for thousands of years, and jewelry that undergoes this process is more valuable than other types of jewelry that has gold added to it in a different way. In gold-plated jewelry, the gold is plated on top of the metal and doesn't last as long as gold overlay.Full Answer >
Gold-plated jewelry consists of a lower-quality base metal coated with a very thin layer of gold through a chemical process, while gold-filled jewelry has a thicker layer of gold bonded to a base metal through heat and pressure. Although both gold-plated and gold-filled jewelry consist of a base layer covered with gold, they differ in the process used to attach the gold and the thickness of the gold.Full Answer >