Topaz is one of the most wanted gemstones in the market. The variety of topaz which is considered the most typical color is yellow topaz. The yellow colors range from brownish yellow to pure, bright yellow to an almost orange color. Many yellow topaz are developed in labs, but yellow topaz also occurs naturally and is generally relatively inexpensive compared with other topaz color. The most common colors of untreated topaz are pale yellow, brown, and gray. Violet and pink Topaz are also found. Since these colors are hardly ever vivid, topaz are often get treatment to produce and enhance more exciting color and luster.

The most popular color, undoubtedly, is blue. Blue topaz is definitely becomes the best selling jewelry stone in the world. Its combination of excellent brilliance, luster and clarity in a very attractive price allow it to posses great values. However, natural blue topaz is rarely found in nature. Most of the blue topazes are enhanced from the colorless topaz. Another expensive variety of topaz is a pink topaz.  A natural untreated pink topaz is extremely rare and very expensive. Most of  pink topazes on the market today are heat-treated yellow stones that turn pink. Today, the most important deposit of Topaz is found in Brazil.

The treatment for natural topaz is commonly irradiation. The blue topaz begins from colorless or very lightly tinted natural topaz crystals. The gems are then irradiated to change the color to blue and heated to stabilize the change. Another method is Neutron bombardment in a nuclear reactor. This method can produces the deep slightly greenish or grayish "London Blue". When neutron bombardment has been utilized, there is definitely residual radioactive that still left on the gems. Therefore, the gems must be held, for more than a year.After the gems are clean enough, no contain of radioactive, the topaz are ready to be worn as jewelery.