Difference between revisions of "Benitoite"
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== Description == | == Description == | ||
| − | A deep blue, sapphire-like gemstone with fiery yellow flashes. Benitoite is composed of a barium-titanium silicate. These rare and valuable crystals | + | A deep blue, sapphire-like gemstone with fiery yellow flashes. Benitoite is composed of a barium-titanium silicate. These rare and valuable crystals were first found close to the San Benito River in California, but have since been found in Montana, Arkansas, Australia, and Japan. Benitoite stones were formerly cut and sold as [[sapphire|sapphires]]. |
| + | [[File:Benitoite IR-ATR RRUFF R050320.png|thumb|IR spectrum of benitoite from [https://rruff.info/benitoite/display=default/R050320 RRUFF]]] | ||
| + | [[File:Benitoite Raman RRUFF R050320.png|thumb|Raman spectrum of benitoite from [https://rruff.info/benitoite/display=default/R050320 RRUFF]]] | ||
| + | == Physical and Chemical Properties == | ||
| + | |||
| + | * Hexagonal crystal system with tabular dipyramidal crystals | ||
| + | * Fracture = conchoidal to uneven | ||
| + | * Luster = vitreous | ||
| + | * Transparent to translucent | ||
| + | * Streak = white | ||
| + | * Fluorescence = blue stones fluoresce bright to chalky blue in SW; colorless stones fluoresce red under LW | ||
| + | * Pleochroism = strong, usually blue and colorless | ||
{| class="wikitable" | {| class="wikitable" | ||
| Line 8: | Line 19: | ||
! scope="row"| Composition | ! scope="row"| Composition | ||
| BaTi(SiO3)3 | | BaTi(SiO3)3 | ||
| + | |- | ||
| + | ! scope="row"| Mohs Hardness | ||
| + | | 6.0 - 6.5 | ||
| + | |- | ||
| + | ! scope="row"| Density | ||
| + | | 3.65 - 3.68 g/ml | ||
| + | |- | ||
| + | ! scope="row"| Refractive Index | ||
| + | | 1.756-1.757, 1.802-1.804 | ||
| + | |- | ||
| + | ! scope="row"| Birefringence | ||
| + | | 0.046 | ||
|} | |} | ||
| − | == | + | ==Resources and Citations== |
| − | + | * Gem Identification Lab Manual, Gemological Institute of America, 2016. | |
* Thomas Gregory, ''The Condensed Chemical Dictionary'', Reinhold Publishing, New York, 3rd ed., 1942 | * Thomas Gregory, ''The Condensed Chemical Dictionary'', Reinhold Publishing, New York, 3rd ed., 1942 | ||
| − | |||
* R.F.Symmes, T.T.Harding, Paul Taylor, ''Rocks, Fossils and Gems'', DK Publishing, Inc., New York City, 1997 | * R.F.Symmes, T.T.Harding, Paul Taylor, ''Rocks, Fossils and Gems'', DK Publishing, Inc., New York City, 1997 | ||
| − | + | * Wikipedia: [https://en.wikipedia.org/wiki/Benitoite Benitoite] Accessed Dec 2022 | |
| − | * ''Encyclopedia Britannica'', | + | * ''Encyclopedia Britannica'', https://www.britannica.co,m/topic/Britannica-Online Comment: "Mineral." Accessed 12 May 2004 . |
[[Category:Materials database]] | [[Category:Materials database]] | ||
Latest revision as of 11:45, 17 December 2022
Description
A deep blue, sapphire-like gemstone with fiery yellow flashes. Benitoite is composed of a barium-titanium silicate. These rare and valuable crystals were first found close to the San Benito River in California, but have since been found in Montana, Arkansas, Australia, and Japan. Benitoite stones were formerly cut and sold as sapphires.
IR spectrum of benitoite from RRUFF
Raman spectrum of benitoite from RRUFF
Physical and Chemical Properties
- Hexagonal crystal system with tabular dipyramidal crystals
- Fracture = conchoidal to uneven
- Luster = vitreous
- Transparent to translucent
- Streak = white
- Fluorescence = blue stones fluoresce bright to chalky blue in SW; colorless stones fluoresce red under LW
- Pleochroism = strong, usually blue and colorless
| Composition | BaTi(SiO3)3 |
|---|---|
| Mohs Hardness | 6.0 - 6.5 |
| Density | 3.65 - 3.68 g/ml |
| Refractive Index | 1.756-1.757, 1.802-1.804 |
| Birefringence | 0.046 |
Resources and Citations
- Gem Identification Lab Manual, Gemological Institute of America, 2016.
- Thomas Gregory, The Condensed Chemical Dictionary, Reinhold Publishing, New York, 3rd ed., 1942
- R.F.Symmes, T.T.Harding, Paul Taylor, Rocks, Fossils and Gems, DK Publishing, Inc., New York City, 1997
- Wikipedia: Benitoite Accessed Dec 2022
- Encyclopedia Britannica, https://www.britannica.co,m/topic/Britannica-Online Comment: "Mineral." Accessed 12 May 2004 .