Pure or 24-karat gold is yellow and relatively soft.
White gold includes an alloy of nickel and palladium.
Zinc is added to harden the gold for gem settings.
White gold can be more expensive than pure gold because it’s harder to fabricate.
18-karat yellow gold is the most popular in Europe and is 75 percent pure gold. 18-karat white gold is 25 percent nickel.
24-karat gold is 99.9 percent pure gold, 22-karat gold is 91.67 percent, and 20-karat gold is 83.33 percent.
20-karat and above is yellow in color.
In America 14-karat yellow gold is the most popular. 14-karat white gold is harder and yellowish and used in prong settings.
It’s often plated with rhodium, a form of platinum, to enhance the whiteness.
12-karat gold is 50 percent gold. It is commonly used in class rings and can be a number of colors depending on the added alloy.
10k gold is 41.67 percent gold and is the lowest alloy to be called gold.