Topaz makes an ideal gem. A good hardness and desirable colors, combined with a relative abundance and availability makes it one the most popular gemstones.

Topaz can be found in colors including yellow, orange, brown, red, blue, pink, red, violet and green, with colourless, or white Topaz also fairly common. The most valuable Topaz colour is an orange to pink color known as Imperial Topaz.

Blue was once the rarest colour of Topaz, but today it is the most common, thanks to a stable colour enhancement process developed in the 1970s. These techniques produce a deep blue with a slight green tone, known as "London Blue". Blue Topaz occurs very rarely in nature, and then only in a very pale blue.

The most common colors of natural untreated Topaz are pale yellow, brown and grey. Pastel shades of light green, violet and pink are also found. Since these colours are rarely vivid, they are often treated to produce more exciting hues. Because Topaz is readily available and affordable, it can be found in a wide variety of shapes and sizes, including unusual cuts. Large dramatic gems are readily available.