Whether the source is a fast-fashion emporium or a high-end retailer, most gold jewelry isn't pure. It's a mix of metals, the majority being untarnishable, noncorrosive, indestructible, $1,175-per-ounce gold.
And that mix determines color, which can be yellow, white, green, rose and red.
Twenty-four-karat gold — pure gold — is a reddish yellow, a hue that is
unmistakably rich and bright. (And it's generally considered to be too
soft to be used in jewelry.)
Everything beyond that is a mix that yields different colors depending
on the percentages of the metals melted together. An item made from
18-karat gold, for example, is 18 parts pure gold and 6 parts alloy, or
75% gold and a 25% alloy mix; 14-karat — the most common form of gold
used in jewelry in the U.S. — is 14 parts pure gold and 10 parts alloy,
or 58% pure gold.
