Difference between revisions of "Topaz"
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*[http://mineral.galleries.com/minerals/silicate/topaz/topaz.htm Amethyst Galleries] | *[http://mineral.galleries.com/minerals/silicate/topaz/topaz.htm Amethyst Galleries] | ||
*[http://www.mindat.org/min-3996.html Mindat.org] | *[http://www.mindat.org/min-3996.html Mindat.org] | ||
Latest revision as of 20:41, July 13, 2016
| Topaz | |
|---|---|
| |
| Chemical name | Aluminum silicate fluoride hydroxide |
| Chemical formula | Al2SiO4(F, OH)3 |
| Identification | |
| Colors | Colorless, white, pale blue, light green, yellow, yellowish brown, or red |
| Crystal habit | Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline). |
| Crystal system | Orthorhombic |
| Cleavage | Perfect (001) |
| Fracture | Irregular/Uneven, Sub-Conchoidal |
| Hardness | 8 |
| 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 |
| Streak | White |
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.
Gallery
Topaz sample
