Fancy color diamonds include yellow, blue, pink, green, red, and a few others. The color of most diamonds comes from trace particle impurities that are present in the carbon lattice structure of the stone as it grows below the Earth. The most common trace element in diamonds is nitrogen, which imparts a yellowish or brown tint to the diamonds, depending on its concentration. Diamonds with nitrogen impurities are called Type Ia diamonds, and represent about 98% of all gem-quality natural stones in the world. Even D-color diamonds can have trace amounts of nitrogen, but the concentration is so small that it cannot be detected without sophisticated lab equipment.