|Chemical name||Aluminum silicate fluoride hydroxide|
|Chemical formula||Al2SiO4(F, OH)3|
|Colors||Colorless, white, pale blue, light green, yellow, yellowish brown, or red|
|Crystal habit||Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).|
|Name origin||Named after Topasos Island in the Red Sea. In antique times, the name was probably used for the gemstone that is now known as peridot.|
|Specific gravity||3.5 - 3.6, Average = 3.55|
Topaz is one of the hardest minerals rating an 8 on the Mohs hardness scale. Chemically, topaz is Aluminum silicate fluoride hydroxide Al2SiO4(F, OH)3 and is classified as a silicate. It is commonly used as a gemstone and its crystals can grow to a very large size. Topaz is commonly a shade of yellow or orange, but may also be colorless and is found in the blue and green ranges. Topaz is the birthstone for November.