Gold by the Numbers

Yellow, rose and white 18-karat gold and diamond ear clips, signed Bulgari, circa 1970s.
Coral, emerald and 18-karat gold dragon ring, signed Van Cleef & Arpels, circa 1970s

When you look at gold jewelry, you may notice that the color of the metal varies from piece to piece and you’ll be right about that. You may also notice that gold jewelry is stamped either 14-karat or 18-karat. So why are the tones of gold different from piece to piece and what exactly are karats? Karats are a measure of gold purity and the karatage of the gold may in some cases affect its color.

Karats Mean Gold Purity

Karat measures the purity, or amount of gold, in a piece of jewelry. Pure gold, which is 24-karats, is soft and very malleable and would not stand up to daily wear, so it is not used in jewelry making. To make gold strong enough for everyday wear, it is mixed with other metals. When two or more metals are mixed together it is called an alloy.

Victorian 15-karat gold pendant earrings

When mixing gold with another metal, the starting point is pure 24-karat gold. When another metal is added it will change the purity of the gold, which affects the color of the metal as well. This is where it gets a little mathematical. If a piece is stamped 18-karat, that means that it is 18 out of 24 parts gold and 6 parts alloy, 14-karat means 14 out of 24 parts are gold and 10 parts are alloy. Both 14-karat and 18-karat gold are the standards in the U.S. and much of the rest of the world.

There is also 22-karat gold which is very high gold content and is usually used in special pieces. The particular color and feel of 22-karat gold makes it a favorite in Asian countries. You may also find 9-karat or 10-karat gold, but not often. In vintage jewelry you will sometimes find 15-karat gold which was used in England for a brief time between 1854 and 1931, when the standard changed to 14-karat gold.

What is an alloy made of? Different metals are used to make an alloy. Cooper, silver, palladium, manganese and/or nickel are mixed with gold. The amount of alloy used will affect the color of the gold. When you compare 18-karat yellow gold to 14-karat yellow gold, you will see a big difference in the color. The higher karat gold will have a richer, deeper color, while the lesser karat gold will be lighter in color.

Alloys Turn Gold Pink or White

Retro 14-karat yellow and rose gold bracelet

Alloys can also be used to create white or rose gold, also called pink gold. Both pink and white gold can also be either 14-karat or 18-karat gold. Rose gold with its warm tones are flattering to any skin tone, it is created by mixing copper with yellow gold. The color is sometimes made lighter by adding a little silver into the mix.

White gold is created by mixing yellow gold with silver, palladium, manganese or nickel.  Nickel is generally not used as many people are allergic to it. Once the white metals have been mixed with the yellow gold, it will still be a creamy color with a grayish undertone. To get the bright shiny white finish that we are used to seeing, the gold is often rhodium plated. Rhodium is a metal in the platinum family that is very durable. When rings  are worn a lot, the rhodium plating may wear away and you will need to get your jewelry freshened up. A rhodium dip is pretty easy. Your jewel is held in tongs and the piece is then dipped into a container of liquid rhodium for a very short time (seconds). When the procedure is done, your piece will look as new as when you first purchased it. The rhodium won’t harm or adhere to most gemstones.

Your Choice of Color

Matelassé 18-karat white gold bracelet, signed Chanel.

How do you decide which color gold is best for you? You may be drawn to the rich color of yellow gold, the warmth of rose gold, or the sleek tones of white gold. Select the color that you like best or that looks best with your skin tone. But here’s the good news… you don’t have to pick just one, you can have pieces in all three gold colors that you can wear separately or together. The choice is yours.

Top of Page: Yellow, rose and white 18-karat gold and diamond ear clips, signed Bulgari, circa 1970s.

Coral, emerald and 18-karat gold dragon ring, signed Van Cleef & Arpels, circa 1970s; Victorian 15-karat gold pendant earrings; Retro 14-karat yellow and rose gold bracelet; Matelassé 18-karat white gold bracelet, signed Chanel.

Authored by Amber Michelle