stishovite
Sign in to savethumb|Pressure-temperature diagram for various forms of silicon dioxide, including stishovite (at top left)
Key facts
- Mineral.mohs
- 9.5
- Mineral.name
- Stishovite
- Mineral.category
- Tectosilicate minerals
- Mineral.group
- Quartz group
- Mineral.image
- stishovite.png
- Mineral.caption
- Crystal structure of stishovite
- Mineral.formula
- SiO2
- Mineral.IMAsymbol
- Sti
- Mineral.strunz
- 4.DA.40 (Oxides)
- Mineral.system
- Tetragonal
- Mineral.class
- Ditetragonal dipyramidal (4/mmm) H–M symbol: (4/m 2/m 2>/m)
- Mineral.symmetry
- P42/mnm (No. 136)
- Mineral.unit cell
- a = 4.1772(7) Å, c = 2.6651(4) Å; Z = 2
- Mineral.color
- Colorless (when pure)
- Mineral.luster
- Vitreous
- Mineral.refractive
- nω = 1.799–1.800 nε = 1.826–1.845
- Mineral.opticalprop
- Uniaxial (+)
- Mineral.birefringence
- δ = 0.027
via Wikipedia infobox
Wikidata facts
- Subclass of
- tectosilicates
- Image
- Stishovite.jpg
Show 8 more facts
- Commons category
- Stishovite
- chemical formula
- SiO₂
- Nickel-Strunz 9th edition (updated 2009)
- 4.DA.40
- Nickel-Strunz '10th ed', review of (9th ed/ 2009 update)
- 4.DA.40
- crystal system
- tetragonal crystal system
- Mohs' hardness
- 9.4
- IMA Mineral Symbol
- Sti
- Strunz 8th edition (series ID, updated)
- IV/D.01b
via Wikidata · CC0
~3 min read
Encyclopedic overview
5 sectionsContents
- Appearance
- Synthesis
- See also
- References
- External links
thumb|Pressure-temperature diagram for various forms of silicon dioxide, including stishovite (at top left)
Stishovite ( ) is an extremely hard, dense tetragonal form (polymorph) of silicon dioxide. It is very rare on the Earth's surface; however, it may be a predominant form of silicon dioxide in the Earth, especially in the lower mantle.
Excerpted from Wikipedia’s “stishovite” article, available under the CC BY-SA 4.0 licence.