Amethyst Galleries
Amethyst Galleries: Mineral Gallery: The Mineral Topaz
This source provides general information on topaz. Some of the facts include classification, and physical charateristics.
Other
International Colored Gemstone Association: Topaz
This site gives a historical perspective of topaz, as well as its physical properties and where it is found. Also provides more information and pictures of the gem itself.
Wikimedia
Wikipedia: Topaz
This encyclopedia article from Wikipedia provides a general overview of the gemstone topaz. Liinks are provided for additional information on related subjects.
Jewelry Central
Jewelry Central: Topaz
This commercial site contains information about the physical and metaphysical properties of topaz, along with where it is found. Discusses the different color variations, and how this gem is enhanced to make it blue.