Composition of Gold Alloys in Colored Gold Jewelry

Rose, white, and yellow gold all contain the metal gold. Colored gold contains other elements, too.
Dorling Kindersley / Getty Images
By
Anne Marie Helmenstine, Ph.D.
Anne Marie Helmenstine, Ph.D.
Chemistry Expert
  • Ph.D., Biomedical Sciences, University of Tennessee at Knoxville
  • B.A., Physics and Mathematics, Hastings College
Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels.
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Updated on December 08, 2019

When you buy gold jewelry, it isn't pure gold. Your gold is really an alloy, or mixture of metals. The purity or fineness of gold in the jewelry is indicated by its karat number—24 karat (24K or 24 kt) gold is as pure as gold gets for jewelry. Gold that is 24K is also called "fine gold" and is greater than 99.7% pure gold. "Proof gold" is even finer, with over 99.95% purity, but it is only used for standardization purposes and is not available for jewelry.

So, what are the metals that are alloyed with gold? Gold will form alloys with most metals, but for jewelry, the most common alloying metals are silver, copper, and zinc. However, other metals may be added, especially to make colored gold. Here's a table of the compositions of some common gold alloys:

Gold Alloys

Color of Gold Alloy Composition
Yellow Gold (22K) Gold 91.67%
Silver 5%
Copper 2%
Zinc 1.33%
Red Gold (18K) Gold 75%
Copper 25%
Rose Gold (18K) Gold 75%
Copper 22.25%
Silver 2.75%
Pink Gold (18K) Gold 75%
Copper 20%
Silver 5%
White Gold (18K) Gold 75%
Platinum or Palladium 25%
White Gold (18K) Gold 75%
Palladium 10%
Nickel 10%
Zinc 5%
Gray-White Gold (18K) Gold 75%
Iron 17%
Copper 8%
Soft Green Gold (18K) Gold 75%
Silver 25%
Light Green Gold (18K) Gold 75%
Copper 23%
Cadmium 2%
Green Gold (18K) Gold 75%
Silver 20%
Copper 5%
Deep Green Gold (18K) Gold 75%
Silver 15%
Copper 6%
Cadmium 4%
Blue-White or Blue Gold (18K) Gold 75%
Iron 25%
Purple Gold Gold 80%
Aluminum 20%
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Helmenstine, Anne Marie, Ph.D. "Composition of Gold Alloys in Colored Gold Jewelry." ThoughtCo, Apr. 5, 2023, thoughtco.com/composition-of-gold-alloys-608016. Helmenstine, Anne Marie, Ph.D. (2023, April 5). Composition of Gold Alloys in Colored Gold Jewelry. Retrieved from https://www.thoughtco.com/composition-of-gold-alloys-608016 Helmenstine, Anne Marie, Ph.D. "Composition of Gold Alloys in Colored Gold Jewelry." ThoughtCo. https://www.thoughtco.com/composition-of-gold-alloys-608016 (accessed May 30, 2023).