All that glitters is not gold, a lot of gold jewellery is gold plated. What this means that a layer of gold is applied on the surface of some other type of metal. There is nothing wrong with gold plating except if it is used to fool buyers of gold. Most Plating is used to enhance the beauty and wearability of jewellery by saving money.
When it comes to the production of fake gold, there are basically two ways to go about it. You can either plate the jewellery or fill an otherwise worthless metal with gold.
Gold plating involves the coating of a metal usually, nickel, copper or silver with a thin layer of gold by applying an electrical current. Ions in the metal attract oppositely charged ions in a chemical solution with gold. The bond created results in a film or layer of gold coating the metal. The thickness of the coating is usually about 0.0002 inches but it can be increased by leaving the metal in the electroplating solution for longer. The electricity helps create a chemical bond that will not easily fall or flake off. When done correctly, gold plating can last many months or even years. If it’s well made and well taken care of, it may be hard for the untrained eye to tell whether jewellery is real gold or the fake kind.
Modern electroplating starts with some thorough cleaning. A metal salt is created with positive charged ions on the base metal combined with an acid. The salt is mixed with water to form a bath. You then apply an electric current to what you want to coat and immerse it in the bath. Gold molecules in this bath ride the current and ions with opposite charge are attracted to each other and a film of gold forms on the surface.
There is another way of getting a gold coating on a metal besides electroplating. Some gold jewellery is gold-filled. There are some significant differences between gold-plated and gold-filled jewellery.
- Gold-filled jewellery is required to contain 5% gold by weight.
- There are two or three layers of metal in gold filled jewellery. The core metal is brass. You can have a single gold cladding or you could have double clad gold where gold is clad on both sides of the material and then bonded to both surfaces of the core by applying heat or pressure. The bonded material is sold as a sheet or wire to be used in jewellery manufacturing.
- Gold-filled jewellery is more durable than gold plated jewellery. It does not tarnish and does not produce the allergic reaction that many people complain of from metals like nickel.
Gold filled jewellery also has a thicker layer of gold and is of a higher quality. It can be hard to tell the difference between, real gold and fake gold, especially high quality gold-filled jewellery. It takes an experienced eye to tell the real from the fakes. Experienced buyers of gold will conduct XRF tests and likely take a closer look by cutting into gold jewellery at what they are buying before they buy anything.