Three stone engagement rings are among the hottest styles in the diamond jewelry market these days. You can even get these with your choice of metal – yellow gold, white gold, or rose gold.     Rose Gold This has been one of the more popular metals among jewelers as far back as the eighteenth century, although the color itself has seen a recent rise in popularity in the past decade. Rose gold is technically an alloy of gold, with some copper blended in to make the otherwise weak metal stronger and more durable. Many people think of vintage designs when they think of rose gold. A 1 carat three stone diamond ring looks especially gorgeous with this metal.   White Gold This is a wise choice if what you are looking for is something sophisticated. White gold is an alloy, but it does not use copper. Instead, you have one of the whiter metals such as nickel, silver, or palladium in the mix. In engagement rings, the white gold is plated with rhodium, so that it has a shiny appearance.