Topaz is a very popular gemstone. Gem quality topaz most commonly occurs in nature as a colorless crystal. When cut as a gemstone these colorless specimens generally have the lowest value. A significant amount of natural topaz also occurs in a color range spanning from yellow to brown. Small amounts of natural blue and pink topaz are found but the abundance of natural stones in these colors is very low.

Treated Topaz Gemstones

 

Blue topaz is a very popular gemstone but this color is rarely found in nature. To produce blue topaz, some dealers irradiate clear topaz then heat it to produce a blue gemstone. The most desirable blue topaz stones have a color that resembles aquamarine. Today, most of the blue topaz being sold as a gemstone has been treated. Dealers should label these stones as "treated" or "enhanced" so that customers know the stone's history. The price of blue topaz has declined in recent years because so much blue topaz has been produced through treatment.

A small amount of topaz occurs naturally as pink and red crystals. These are the most expensive colors of natural topaz. However, brown topaz can sometimes be heat treated to produce a pink stone.