White Gold
18 karat white gold is a very common jewelry material and is often used in watchcases and bracelets, especially as a less expensive, similar-looking alternative to platinum. By weight it is usually 75% gold, 3% silver, 12.5% palladium and 9.5% copper (although combinations of gold, silver, nickel, zinc and copper are used quite often). Although very expensive, the addition of palladium (or even less costly nickel and zinc) makes this form of gold very hard compared to most others. And because white gold has such a low percentage of copper content, it is the least likely gold alloy to cause an allergic reaction. Moreover, 18k white gold polishes well, resists scratching and is one of the two densest colors of gold.