White gold is an alloy of gold. It is made by mixing pure gold with silvery white metals such as silver and palladium. It was originally developed to imitate platinum, a precious white metal. In the industry, the term "white gold" is often used to describe carat gold alloys with a whitish hue. The word "white" refers to a wide range of colors that overlap with pale yellow, pale pink and brown hues. The characteristics of white gold depend on the metal alloys and their proportions. Therefore, white gold alloys can have several different applications.
What is white gold made up of? White gold is composed mainly of gold and a mixture of dense metals such as copper, zinc, nickel, rhodium or palladium. The white color is achieved by carefully selecting alloying metals that discolor the reddish-yellow color of pure gold. The amount of gold is measured by a unit called a carat (K). In 24-carat gold, all 24 parts of the gold are pure gold with extremely low levels of impurities. Similarly, 18k gold contains 75% (or 18/24) gold and 22k gold is 91.6%. The percentage of alloy added affects the overall longevity and final color of the gold. For example, 22k gold is more durable and has a more yellowish hue than 18k gold. Generally, white gold is marked 18 karat. It contains 75% gold and about 25% nickel and zinc. Some types of white gold contain 90 percent gold and 9.5 percent nickel. Small amounts of copper are added to make it more malleable. White gold used in jewelry is an alloy of gold-nickel-copper-zinc or gold-palladium-silver. Nickel and palladium act as primary bleaching agents to reduce the color of gold, and zinc acts as a secondary bleaching agent for copper.
Why is gold alloyed with other metals? Because pure gold is a very soft and malleable metal, it is alloyed with a mixture of metals to increase strength and durability in order to be used to make jewelry. In fact, the gold you see in any industry is rarely pure. Some impurities (such as mercury) are added even before alloying to produce white gold. Without harder alloys, pure gold wouldn't be able to retain its desired shape - the gold itself would be too soft.
Some white gold jewelry is additionally coated with rhodium, a rare silvery-white metal. It enhances the luster and durability of your jewelry by making it smooth and shiny. How is gold different from platinum? Although they are very similar in appearance, platinum and white gold are different metals. They have their own properties and advantages that make them unique. Platinum is a precious silver-white metal that does not need to be alloyed to impart color. It is less common than gold and is more durable and dense than white gold. Unlike white gold, platinum jewelry is purer: it contains 95-98% platinum and 5-3% silver and rhodium. Because gold jewelry contains more alloys (which are sort of necessary for extra strength and durability), they cost less than platinum jewelry. Both metals have the same cost per ounce (about $1,900 per ounce), but it takes more platinum to make jewelry because it is more dense. Because of its higher melting point, platinum is harder to work with. These are some reasons why platinum rings cost more than white gold rings. Another major difference is that 22k, 18k or 14k gold is harder to scratch than platinum. Also, gold jewelry requires less cleaning and polishing. This is not the case with platinum jewelry -- the cost to maintain it is quite high, since it must be cleaned and polished at intervals in order to keep it smooth and shiny.
However, both white gold and platinum have the same white color. With the naked eye, it's hard to tell the difference.
Advantages and Disadvantages of White Gold Like any other alloy, white gold has its advantages and disadvantages. Advantages It will not rust, tarnish or corrode. Compared to rose gold, white gold can be blended with stronger metals, making jewelry more scratch-resistant and durable. The cost is 50% lower than platinum jewelry. White gold can have more intricate designs than platinum. Disadvantages The rhodium coating rubs off over time, so it must be replaced every few years. Requires cleaning and polishing every few years to keep it smooth and shiny. However, this is a fairly simple and inexpensive process. Nickel-alloyed white gold can cause an allergic reaction in some people. Other types of colored gold Pure gold is a soft, slightly reddish-yellow metal. However, when alloyed with harder metals, it forms a range of colors, including yellow, red, green, purple, blue and black. Yellow gold: Has a unique warm glow. It is considered more traditional than white gold. Unlike white gold and platinum, which look the same, yellow gold is difficult to imitate. It is usually alloyed with copper and silver. Most 18k yellow gold pieces contain 75% gold, 12.5% copper and 12.5% silver. A darker yellow color is achieved by increasing the amount of copper to 15%. Rose gold and red gold: seem similar, but the difference is the copper content. The higher the concentration of copper in the alloy, the darker the red color. Red gold contains the most copper, while rose gold contains the least. Sometimes zinc is added to the alloy to give a reddish-yellow color. 18K rose gold contains 75% gold, 20% copper and 5% silver; 18K rose gold has the same amount of gold with 22% copper, 4% silver; and 18K red gold contains 25% copper and no silver. Red gold 12K contains gold and copper in equal proportions. Blue gold: is an intermetallic compound obtained by mixing gold with indium or gallium. The former contains 54% indium and 46% gold, while the latter contains 59% gold and 41% gallium. Purple gold: This is an alloy of gold (79%) and aluminum (21%). These intermetallic compounds are quite rare and more brittle than most gold alloys. Ferrous gold: produced by a variety of surface treatments. Gold alloys with high copper content can be colored from black to brown by treating them with potassium sulfide. Black gold can also be produced by controlled oxidation of gold alloys containing cobalt or chromium, or by creating nanostructures on the surface with a femtosecond laser. Gray gold: usually produced by mixing gold (75-76%) with palladium (15-23%) and rhodium (1-5%). 18K gray gold can also be produced without bleaching elements such as palladium, nickel and cobalt - this inexpensive alternative includes 75-78% gold, 7-15% manganese, 1-10% silver and 1-2% copper. Green gold: made by adding 4% cadmium. Its use is usually reduced because cadmium is toxic.
Frequently Asked Questions Does white gold occur in nature? No, white gold is not found in nature. It is made by hand by adding silvery white metals. The first versions of white gold were created in 18th century Germany. However, white gold, which replaces platinum, was first produced in the 1920s. How rare is white gold? White gold is not that rare because it is made from gold, which is often found in free elemental (native) form as well as in minerals. Platinum, however, is very rare. It is one of the rarest metals in the Earth's crust, with an average content of about 5 micrograms per kilogram. Since only a few hundred tons are produced each year, platinum is one of the major precious metals. Can regular white gold turn yellow? Nowadays, almost every piece of white gold jewelry is plated with rhodium (a silver-white metal), so it does not yellow or tarnish when worn normally. However, this coating must be changed every few years. Otherwise, the rhodium will fade, revealing the true colour of the white gold. Can a hand sanitizer damage my white gold jewelry? Yes, anything containing alcohol can damage white gold jewelry. Because alcohol is corrosive, it can gradually corrode the metal finish of your jewelry. If the disinfectant contains too much alcohol, it can cause white gold jewelry to lose its luster faster. White gold contains cheaper alloys, which means that the purity (carat) of your gold jewelry decreases. This is the reason why white gold has a lower resale value than 22K or 18K yellow gold. If you are buying jewelry for investment purposes, it is better to choose a purer, reddish-yellow gold or silver-white platinum.