18 karat gold is a concentration of 75% gold, and 25% other metals/elements. The 75% gold content ensures that the gold alloy will have all of the desirable properties of pure gold, while the other 25% allows the metal to be strong enough to retain its shape and survive the rigors of everyday use. Depending on what other metals/elements make up the additional 25% of the 18k gold mixture, the color of the gold alloy can be influenced to achieve an impressive range of different hues.
One of the more popular colors of gold is rose/pink gold, which has a warmer and more red-colored appearance than traditional yellow gold. Pure gold in its elemental form is only ever a yellow-colored metal, so in order to achieve the pink/red tones of rose gold, copper is added to the gold mixture, which darkens its color and gives the rose gold mixture its signature warm appearance. Generally speaking, the more copper that gets added to the gold mixture, the darker and more red-tinted its color will be.
Although pure gold is prized for its non-reactive properties, and will not tarnish or oxidize under normal conditions, copper will readily react when left unprotected, and the naturally red-colored metal will quickly begin to develop a pale green outer layer (known as a patina) on any surfaces that are exposed to the elements. The patina that develops actually protects the copper below the surface from further corrosion; however it significantly changes the appearance of the once red-colored item.
Most traditional rose gold alloys, regardless of their copper content, will begin to lose their red/pink coloration after prolonged use and exposure to sweat, oxygen, salt water, and chlorine. As the copper molecules in the gold alloy react and begin to discolor, the external surfaces of the rose gold item will slowly start to loose their once red/pink tones. Since it is only the surface layer of the rose gold that loses its color, polishing the metal will restore its red/pink appearance; however it is not uncommon to encounter an older, rose gold watch that has lost almost all of its red/pink coloration and now closely resembles a yellow gold timepiece.
Rolex’s Everose Pink Gold.
In 2005, Rolex announced a new type of proprietary pink gold called Everose, which Rolex specifically designed from inside their in-house foundry, to retain its red/pink hue. Along with precise amounts of copper and silver, a tiny bit of platinum is added to the 18 karat gold mixture, which locks in its color, and prevents its surface layer from discoloring, even after prolonged exposure to saltwater and chlorine.
It has been over 13 years since Rolex first introduced their proprietary Everose pink gold to the public, and their initial claims about its ability to retain its color have held true. While it is quite common to encounter vintage rose gold timepieces that have lost their signature red/pink coloration, the majority of modern Rolex watches craft from Everose will appear just as rose-colored as they did when they first left the Rolex factory.
If you have an older pink gold Rolex watch that is starting to look dull and not as rosy as it once did, the polishing and refinishing process that is included with every Rolex overhaul we perform will remove minor blemishes and restore the once vibrant, red/pink hues to the metal of your watch.