Mystic fire topaz is a comparatively recent development in treated topaz that first appeared sometime around 1998. The coloration of the stone does not occur naturally but through a process in which very thin layers of titanium are applied to clear topaz. The result is a rainbow stone featuring very deep greens and purples.
The U.S.-patented process binds titanium atoms directly to the stone, which gives it an iridescent and kaleidoscopic quality. The vivid coloration of mystic fire topaz is what gives it its name. It is also called "rainbow topaz" and "fire topaz," and it has gained popularity in recent years.
Although mystic fire topaz is relatively new, the topaz gem has been popular in many cultures for thousands of years. Ancient Egyptians venerated the stone, and topaz can be found in many regions all over the world. Its popularity is due to its hardness as well as its clarity. Not nearly as expensive as diamonds, topaz is often used as a less expensive substitute, and it has gained popularity as the setting in engagement rings. Larger topaz stones have deeper colors and greater color variations than smaller stones. While greens and purples have been strongly associated with mystic topaz, new color choices include Java Blue and Mercury Mist.