Gold's ductility, malleability, rich color, and purity are what allowed goldsmiths thousands of years ago to make it into jewelry. It is commonly alloyed in to a slew of colors, including pink, yellow, and white.

Gold purity is measured in karats. Each karat is equivalent to 1/24th purity, so a 24k ring is pure gold. Most high-quality gold jewelry is 18k or 3/4 gold by weight.

Yellow gold is the traditional gold color and is good for slightly yellow diamonds. White gold is good for colorless diamonds and people who prefer the white metals. Pink gold will stand out and is rarely used in engagement rings. I highly recommend it.