Editing Gold plating (section)

== Jewellery ==
Gold plating of silver is used in the manufacture of [[jewellery]]. The thickness of gold plating on jewellery is noted in microns (or micro-meters).  The microns of thickness determines how long the gold plating lasts with usage. The jewellery industry denotes different qualities of gold plating in the following terminology

# Gold flashed / Gold washed - gold layer thickness less than 0.5 micron
# Gold plated - gold layer thickness greater than or equal to 0.5 micron
# Heavy gold plated / Vermeil - gold layer thickness greater than or equal to 2.5 micron

Gold plated silver jewellery can still tarnish as the silver atoms diffuse into the gold layer, causing slow gradual fading of its color and eventually causing [[tarnishing]] of the surface. This process may take months and even years, depending on the thickness of the gold layer. A [[barrier metal]] layer is used to counter this effect; these can be nickel or rhodium. Copper, which also migrates into gold, does so more slowly than silver. The copper is usually further plated with nickel. A gold-plated silver article is usually a silver substrate with layers of copper, nickel, and gold deposited on top of it.