Rose Gold

Rose gold is a gold and copper alloy widely used for specialized jewelry. Rose gold, also known as pink gold and red gold, was popular in Russia at the beginning of the nineteenth century, and was also known as Russian gold although this term is now obsolete. Rose gold jewelry is becoming more popular in the 21st century and is commonly used for wedding rings, bracelets, and other jewelry.
Although the names are often used interchangeably, the difference between red, rose, and pink gold is the copper content: the higher the copper content, the stronger the red coloration. Pink gold uses the least copper, followed by rose gold, with red gold having the highest copper content. Examples of the common alloys for 18K rose gold, 18K red gold, and 18K pink gold:
18K Red gold: 75% gold, 25% copper
18K Rose gold: 75% gold, 22.25% copper, 2.75% silver
18K Pink gold: 75% gold, 20% copper, 5% silver
12K Red gold: 50% gold and 50% copper.^[3]
Up to 15% zinc can be added to copper-rich alloys to change their color to reddish yellow or dark yellow.^[2]
During ancient times, due to impurities in the smelting process, gold frequently turned a reddish color. This is why many Greco-Roman texts, and even many texts from the Middle Ages, describe gold as "red".