Any jewelry that has an overlay of another metal, no matter the means of production, is called plated jewelry. Electroplating is when a base metal is coated in a thin coating of another metal, usually gold or silver, by putting the base metal in a chemical solution and using an electrical current to deposit the layer of other metal. Electroplating was first patented for commercial use in 1840 in Birmingham. The process soon spread around the world. The first modern commercial electroplating center was opened in 1876 in Hamburg.
Jewelry marked H.G.E. or H. G.P. has been gold plated or ‘hard gold electroplated’.
Vermeil is the highest quality kind of goldplated metal, and is made with a sterling silver base coated with gold. Goldtone jewelry is when the jewelry is coated in a gold colored metal that isn’t gold at all; this is common with costume jewelery such as Monet, Napier, Robert and Kramer.
One way to identify gold plated or electroplated jewelry is to look at the corners and edges with a loupe. If there are any worn areas with a different type of metal showing through this means it is plated metal. Another way to test is with an electronic gold tester. Acid test kits can’t differentiate good gold plated jewelry from gold jewelry as the acid only tests the surface of the metal.
Gold Fill or Rolled Gold
Gold Fill is the same as Rolled Gold or Rolled Gold Plate (the first is the American name and the later two are the British names). It is usually more valuable than gold plated metal as it generally contains more gold. Gold-filled or rolled gold jewelry, is composed of a solid layer of gold bonded to a base metal such as brass. This bonding is created with a process using heat and pressure.
In the USA, if the gold layer is 10 kt fineness the minimum layer of karat gold in an item stamped GF must equal at least 1/10 the weight of the total item. If the gold layer is 12 kt or higher the minimum layer of karat gold in an item stamped GF must equal at least 1/20 the weight of the total item. Gold Fill can be identified by fractional numbers and letters surrounding the karat quality mark. Gold Fill is expressed in a fraction: 1/20 10K G.F., for example, translates as: 10 karat gold comprises 1/20 of the weight of this object. Gold-filled is expressed as: GF, gold filled or, in French, double d’or. RGP means ‘rolled gold plate’.
Double clad gold-filled sheet is produced with 1/2 the thickness of gold on each side. 1/20 14Kt double clad gold-filled has a layer on each side of 1/40th 14Kt making the total content of gold 1/20.
Some antique jewelry is made with gold fill with a base of silver and this is considered the highest quality gold fill. Gold Fill was first used in the USA in 1844.
Gold Fill will loose heat faster than solid gold. It may or may not be magnetic, depending on the amount of gold and what base metal has been used. It can be tested with acid testing or an electronic gold tester.
Sources / further reading: