Zircon has wonderful refraction which gives the gemstone lots of fire. Colorless Zircon is the closest natural forming mineral that resembles the diamond. It can also seem to have more than one color also know as pleochroism.
Zircon comes in a myriad of colors from colorless, to blues (Blue Zircon), greens, yellows (Champagne Zircon) and, most commonly, brown.
Zircon is primarily found in Cambodia, Sri Lanka, Vietnam, and Thailand.