White gold is an alloy of gold with other metals that gives the metal a “white” or silvery appearance. It is often comparable in color to platinum, but less expensive. White gold is harder than fine silver or sterling silver and doesn’t tarnish.
Here is a look at the composition of white gold and how it compares with yellow gold and platinum.
White Gold Composition
Gold is a pure element, but it’s used in jewelry and electronics as an alloy, which means it contains other elements. The amount of gold in yellow and white gold is expressed as karats. So, both a 14K yellow gold ring and 14K white gold ring are 14/28 or about 58% gold. Yellow gold contains copper, silver, or other elements that make the metal harder, yet allow it to retain its golden color. White gold is gold alloyed with nickel, palladium, platinum, and/or manganese. Sometimes it contains copper, zinc, or silver. Two common alloys are gold-palladium-silver and gold-nickel-copper-zinc.
White Gold Color and Properties
Most white gold isn’t all that white! Even though most of the non-gold metals in white gold are mostly silver-colored, white gold tends to have a bit of a yellow or dull gray cast. If the alloy contains enough copper, white gold may be slightly pink. Also, the higher the karat value of the gold, the more yellow its appearance. So, 18K white gold is more likely to appear yellow than 14K white gold.
White gold made from gold and palladium has an acceptable pale gold/gray color and may not be coated with another metal. But, most white gold has a electroplating of rhodium or platinum. The coating improves color and shininess and reduces the incidence of allergies or dermatitis from metals in the alloy.
Allergies to White Gold
Usually, if a person reacts to white gold, it’s due to nickel in the alloy. One in eight people are sensitive to nickel-containing alloys. The most common reaction is a skin rash. The gold-palladium alloys tends not to cause a reaction. But, some people experience sensitivity to mercury (common in dental amalgam) if their skin touches gold. Electroplating over the metal isn’t a surefire way to avoid a metal allergy because the coating wears over time and needs replaced every five to ten years.
Comparing Yellow Gold, White Gold, and Platinum
Pure gold is too soft for practical applications, but alloying it as yellow or white gold improves its wear while retaining its corrosion and oxidation (tarnish) resistance. Platinum, in contrast, finds use as a reasonably pure element. Platinum is silver-colored, but darker than silver or rhodium.
- Yellow gold is much stronger than pure gold. Its color never changes, but it does wear down and scratch over time.
- Platinum is more expensive the yellow or white gold, but it’s also the safest choice for persons with sensitive skin. Also, matching platinum jewelry is easier than matching gold jewelry because each gold alloy has a slightly different appearance. But, platinum isn’t invulnerable. It still scratches and requires polishing from time to time.
- White gold is less expensive than platinum. Its cost relative to yellow gold depends on the other elements in the alloy and electroplating (if used). Rhodium-plated white gold has the brightest, whitest appearance and is highly scratch-resistant. Platinum-plated white gold matches platinum jewelry. But, the coating wears, so it’s important that people with sensitive skin maintain electroplated white gold jewelry.
Which metal you choose depends on the color you favor, affordability, and skin sensitivity. A reputable jeweler knows their alloy compositions and can find yellow and white gold options, even for persons with metal allergies.
References
- Benner, L. S. et al. (eds.) (1991). Precious Metals Science and Technology. International Precious Metals Institute: Allentown.
- Cretu, C.; Van Der Lingen, E. (1999). “Coloured gold alloys”. Gold Bulletin. 32 (4): 115. doi:10.1007/BF03214796
- Emsley, John (2003). Nature’s Building Blocks: An A–Z Guide to the Elements. Oxford University Press. ISBN 0198503407.
- Pigatto, P.D.; Guzzi, G. (2017). “Allergy to gold: The two faces of Mercury”. Annals of Dermatology. 29 (1): 105–106. doi:10.5021/ad.2017.29.1.105