The density of topaz varies slightly depending on the specific variety and its chemical composition, but it is generally considered to be:

3.4 - 3.6 g/cm³

Here's a breakdown:

* 3.4 g/cm³ is the density of the most common topaz variety, blue topaz.

* 3.6 g/cm³ is the density of imperial topaz, which is a rare and highly prized variety.

Remember that this is just a general range. If you need a precise density for a specific topaz, you'll need to consult a gemologist or refer to specialized gemological resources.