By far the most common color of gold used in jewelry, yellow gold is gold in its natural shade. Yellow gold is usually alloyed with copper and silver to increase the strength of the metal. How yellow the metal is depends upon the content of gold. A 14-karat piece of jewelry will have a brighter yellow hue than a 10-karat piece. Likewise, an 18-karat piece of jewelry will have a deeper yellow than 14-karat gold, and so on.
Increasing in popularity in recent years, white gold has become fashionable as the preferred cool and contemporary look. White gold boasts the same properties as classic yellow gold, but achieves its white color by mixing with different alloys. In general, white gold is created when a nickel or palladium alloy (zinc and copper) is used. White gold may also be plated with an even whiter metal, such as rhodium, to enhance its cool appearance. As well, a white gold setting can enhance the rapture of white diamonds.
Rose or pink-colored gold can be created by alloying copper with yellow gold. This hue of gold tends to have a pink, bluish tint that complements many skin tones.
This color variation of gold can be created by alloying silver, copper and zinc with yellow gold.
Gold’s softness and malleability make it a wonderful metal to work with when creating virtually any design in jewelry. But this softness can be a drawback as well. To make it stronger and more durable, gold is usually alloyed, or mixed, with other metals such as copper or silver. The higher a metal’s percentage of gold content, the softer and more yellow the jewelry piece. The karat weight system used to measure gold in a piece is the same for all hues, including white and yellow gold. The word “carat” is Arabic, meaning “bean seed.” This is because historically seeds were used to measure weights of gold and precious stones. In the United States, “karat” with a “k” is used to measure gold’s purity, while “carat” with a “c” is used in measuring a gemstone’s size. The karat mark of gold represents the percentage of pure gold to alloy.
24K is pure gold or 100% gold
21K is 21/24ths gold content or 87.5% gold
In the United States, jewelry with this karatage or higher is rare. It is far more common in Europe, the Middle East and Southeast Asia.
18K is 18/24ths gold content or 75% gold
This karatage is a popular high-end choice in the United States, Europe and other regions. Its popularity is spreading throughout North America.
14K is 14/24ths gold content or 58.5% gold
This is the most common gold karatage in the United States because of its fine balance between gold content, durability and affordability.
10K is 10/24ths gold content or 41.7% gold
This karatage is gaining popularity for its affordability and durability. Commonly used in everyday-wear jewelry such as rings, 10K gold beautifully withstands wear and tear. It is the lowest gold content that can be legally marked or sold as gold jewelry in the United States.
Gold Filled, Gold Plated & Vermeil
Alternative types of gold jewelry include gold filled, gold plated and vermeil. Over time, gold plating and vermeil will wear off, requiring re-plating. Gold plating is an electrolytic process in which a gold coating of at least 10K gold with a minimum thickness is affixed to all surfaces.
Vermeil refers to mechanically bonding or electroplating gold with a minimum fineness of 10K over a base of sterling silver.
Gold-filled jewelry consists of a layer of 10K gold or better mechanically bonded to the surfaces of a base (non-precious) metal. This layer of 10K gold must be a minimum of 1/20th of the total metal weight to be called gold filled. Gold-filled items, even with daily wear, can last five to 30 years but will eventually wear through. The gold layer on gold-plated jewelry varies greatly depending on manufacturer, so there is no single, simple comparison. Gold-filled items are 50 to 100,000 times thicker than regular gold plating, and 17 to 25,000 times thicker than heavy gold electroplate
Why Are Other Metals Mixed With Gold?
You’ll find examples of pure gold jewelry, but pure gold is soft and isn’t practical for daily wear. Other metals are mixed with it to make it more durable (and to lower its cost).
Adding other metals to the mix also allows metallurgists to change the color of gold. Palladium or nickel can be added to create white gold. Adding copper produces a rose or pink tint, while silver gives gold a greenish cast.
When metals are added to the gold the result is an alloy, a blended mixture of the metals that you can think of as a very expensive cake batter. Solid gold is a term that can be used to describe an item that’s at least 10K (in the US) gold all the way through. Even though it’s a gold alloy–18K, 14K, or anything down to 10K–it can be called solid gold.