Wondering how rose gold gets that color?
Have you ever wondered why some gold is rose colored, white colored, or sometimes even red, green, or blue? The answer lies not in the gold, but the metals it is mixed with…
Gold, as a pure element, comes from the earth yellow in color. We give the name “24kt” to pure gold. When gold is used in jewelry, it is always combined with other metals to give it extra strength. The mixture of other metals is called an “alloy”. The amount of alloy mixed with gold is revealed by the karat of the resulting mixture. Since most gold is alloyed in standardized measures, we have come to know gold by its “karat”:
- 22k gold is 22 parts gold and 2 parts alloy (91.6% pure)
- 18k gold is 18 parts gold and 6 parts alloy (75% pure gold)
- 14k gold is 14 parts gold and 10 parts alloy (58% pure gold)
- 10k gold is 10 parts gold and 14 parts alloy (42% pure gold)
The alloys in gold are responsible not only for the strength of gold, but also can be used to change the color of gold. When alloying 22kt gold, there is so little alloy that it is difficult to change the color from the rich yellow color so it is almost always some shade of yellow.
However, once the amount of alloy is raised to 25%, as in 18K gold, the alloy metal can be mixed from various metals to create the different colors we see in jewelry.
Yellow gold in any karat is alloyed with differing combinations of copper, silver, and zinc. These metals do not change the color of yellow gold when used together.
The alloy used to make rose gold has a high copper content . The mixture of the yellow and copper colors together result in the warm peachy rose color referred to as Rose or pink gold.
White gold* is most often alloyed with nickel and zinc. Nickel is the alloy which causes most allergic reactions associated with white gold. White gold can also be made using an alloy of platinum or palladium which creates a hypo-allergenic ring, but is more expensive because the alloys themselves are precious. Ritani is one company that alloys all of its white gold with palladium and is a great option for people with allergies to the alloys in white gold.
Gold can also be made in the color of green, alloyed with differing mixtures of silver, copper, and cadmium); Blue gold can be made using an alloy of iron; purple gold can be made with an alloy of aluminum. These materials are not optimal for jewelry fabrication since the alloys tend to harden the metal too much or not enough.
Since 14k rose gold has a relatively high copper content, it can occasionally leave a black residue on your finger. Copper is a highly reactive element and will often react with the PH level of skin or the chemicals in perfume or makeup. The good news is that this will appear and disappear at different times. A good cleaning of the ring and your finger should make it disappear and have you off to a "clean start."
Because of the yellow color of pure gold, these colors all have a faint yellow taint which is only noticeable in white gold. Consequently, white gold is often plated with rhodium to create a pure white coating that lasts anywhere from 6 – 12 months and can be reapplied when worn off.