A blue variety of Topaz used as a gemstone. Naturally occurring blue topaz is very rare. The blue color can be artificially induced in clear topaz crystals by irradiation followed by heat. Blue topaz has often been confused with Aquamarine.
Synonyms and Related Terms
topaze bleue (Fr.); topázio azul (Port.)
Physical and Chemical Properties
- Orthorhombic system with mostly prismatic crystals.
- Perfect cleavage in one direction.
- Fracture = subconchoidal and uneven.
- Luster = vitreous.
- Streak = colorless to white.
- Yellow topaz turns a soft red when heated.
Resources and Citations
- Encyclopedia Britannica, http://www.britannica.com
- Minerals.net at https://www.minerals.net/mineral/topaz.aspx
- Geology.com at https://geology.com/gemstones/blue-topaz/