Topaz occurs in a wide range of natural colors; however, most natural topaz is colorless. The most highly regarded colors are the reds and pinks, which receive their color from trace amounts of chromium. Chromium is also responsible for the color in violet and purple topaz.

A variety known as “imperial topaz” is especially valuable because people enjoy its reddish orange to orangy red colors, which often both occur in the same crystal. Most of the world’s imperial topaz is found in Brazil.

Topaz with a natural blue color is very rare and valuable. Topaz that is yellow, brown, and colorless has a much lower value. However, some natural topaz with these colors can be heated, irradiated, coated, or treated in other ways to alter their color. The fastest selling colors of topaz are varieties of blue that are treated by a process known as irradiation.