Natural fancy color diamonds get their coloring in different ways: From different trace elements present in the stones, such as nitrogen, which produces a yellow diamond. From exposure to radiation during the diamond's creation. Green diamonds are an example of gems affected by radiation. Inclusions, regarded as undesirable in a colorless stone, often contribute unique tones and interesting flashes of color in a fancy color diamond. Making the Color More Intense Fancy color diamonds are more popular than ever, so gemologists have developed ways to create affordable versions by treating less desirable diamonds. Irradiation, followed by a high heat treatment, turns brownish and yellow diamonds into colorful show-stoppers, and at a price you can afford. Treatments make it possible for more of us to own these vivid diamonds, because most natural colored diamonds are rare and expensive. You should assume that any affordable fancy color diamond has been treated in some way. If you question a stone's origins, ask for a lab certificate to verify its authenticity. Synthetic Diamonds are Another Option Synethic colored diamonds are another option. They're real diamonds, but they are created in a lab. Synthetics make owning a fancy color diamond a reality for those of us who couldn't afford a natural stone. http://jewelry.about.com/cs/diamonds/a/colordiamonds.htm Take the tour http://jewelry.about.com/od/diamonds/ss/fancy_color.htm