Keatite
Valid as an unnamed mineral
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Formula:
SiO2
Crystal System:
Tetragonal
Member of:
Polymorph of:
A name originally given to a synthetic tetragonal polymorph of silica (Keat, 1954; Shropshire et al, 1959).
Recently found in ultrahigh-pressure rocks (Hill et al., 2013).
Recently found in ultrahigh-pressure rocks (Hill et al., 2013).
Unique Identifiers
Mindat ID:
2173
Long-form identifier:
mindat:1:1:2173:5
Similar Names
| Ekatite | A valid IMA mineral species | (Fe3+,Fe2+,Zn)12(AsO3)6(AsO3,HSiO4)2(OH)6 |
| Gaitite | A valid IMA mineral species | Ca2Zn(AsO4)2 · 2H2O |
| Goetite | A synonym of Goethite | |
| Katoite | A valid IMA mineral species | Ca3Al2[◻(OH)4]3 |
| Kotoite | A valid IMA mineral species - grandfathered | Mg3[BO3]2 |
| Peatite-(Y) | A valid IMA mineral species | Li4Na12Y12(PO4)12(CO3)4(F,OH)8 |
| Queitite | A valid IMA mineral species | Pb4Zn2(SO4)(SiO4)(Si2O7) |
IMA Classification of Keatite
IMA status notes:
Unnamed (probably valid)
Approval history:
Unnamed, but probably valid.
Classification of Keatite
4.DA.45
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
D : Metal: Oxygen = 1:2 and similar
A : With small cations: Silica family
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
D : Metal: Oxygen = 1:2 and similar
A : With small cations: Silica family
Chemistry of Keatite
Mindat Formula:
SiO2
Elements listed:
Crystallography of Keatite
Crystal System:
Tetragonal
Class (H-M):
422 - Trapezohedral
Space Group:
P43212
Cell Parameters:
a = 7.4462(1) Å, c = 7.4462(4) Å
Ratio:
a:c = 1 : 1
Unit Cell V:
475.93 ų
Z:
1
Comment:
R(F) = 0.037, T = 293 K; Grosskreuz & Marler (2023)
Synonyms of Keatite
Other Language Names for Keatite
Relationship of Keatite to other Species
Member of:
Other Members of Silica:
| Chibaite | SiO2 · n(CH4, C2H6, C3H8, i-C4H10) (n = 3/17 (max)) | Iso. m3(2/m3) : Fd3 |
| Coesite | SiO2 | Mon. 2/m : B2/b |
| Cristobalite | SiO2 | Tet. 422 : P41212 |
| Lechatelierite | SiO2 | Amor. |
| Melanophlogite | 46SiO2 · 6(N2,CO2) · 2(CH4,N2) | Tet. 4/mmm(4/m2/m2/m) |
| Mogánite | SiO2 | Mon. 2/m |
| 'Opal-AG' | SiO2 · nH2O | |
| 'Opal-AN' | SiO2 · nH2O | |
| 'Opal-C' | SiO2 · nH2O | |
| 'Opal-CT' | SiO2 · nH2O | |
| Quartz | SiO2 | Trig. 32 : P3121 |
| 'Quartz-beta' | SiO2 | Hex. 622 : P6422 |
| Seifertite | SiO2 | Orth. mmm(2/m2/m2/m) : Pbcn |
| Stishovite | SiO2 | Tet. 4/mmm(4/m2/m2/m) : P42/mnm |
| Tridymite | SiO2 | Tric. 1 |
| 'β-Cristobalite' | SiO2 | Iso. m3m(4/m32/m) : Fd3m |
| 'β-Tridymite' | SiO2 |
Related Minerals - Strunz-mindat Grouping
| 4.DA. | Bosoite | SiO2 · nCxH2x+2 |
| 4.DA. | Chibaite | SiO2 · n(CH4, C2H6, C3H8, i-C4H10) (n = 3/17 (max)) |
| 4.DA. | 'Carbon Dioxide Ice' | CO2 |
| 4.DA.05 | Quartz | SiO2 |
| 4.DA.10 | Tridymite | SiO2 |
| 4.DA.10 | Opal | SiO2 · nH2O |
| 4.DA.15 | Cristobalite | SiO2 |
| 4.DA.20 | Mogánite | SiO2 |
| 4.DA.25 | Melanophlogite | 46SiO2 · 6(N2,CO2) · 2(CH4,N2) |
| 4.DA.30 | Lechatelierite | SiO2 |
| 4.DA.35 | Coesite | SiO2 |
| 4.DA.35 | Xiexiandeite | SiO2 |
| 4.DA.40 | Stishovite | SiO2 |
| 4.DA.50 | Seifertite | SiO2 |
| 4.DA.55 | 'Quartz-beta' | SiO2 |
Other Information
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Internet Links for Keatite
mindat.org URL:
https://www.mindat.org/min-2173.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Keatite
Reference List:
Keat, P. P. (1954) A New Crystalline Silica. Science, 120 (3113). 328-330 doi:10.1126/science.120.3113.328
Shropshire, Joseph, Keat, Paul P., Vaughan, Philip A. (1959) The crystal structure of keatite, a new form of silica. Zeitschrift für Kristallographie, 112 (1). 409-413 doi:10.1524/zkri.1959.112.1-6.409
RAY, SATYABRATA (1971) Solid Solutions in the Keatite Crystal Lattice. Journal of the American Ceramic Society, 54 (4). 213-215 doi:10.1111/j.1151-2916.1971.tb12269.x
Ferreira da Silva, M.G., Fernández Navarro, J.M. (1989) Formation of keatite from Li2O-SiO2 gels in the presence of chromium oxide. Journal of Non-Crystalline Solids, 109 (2). 191-197 doi:10.1016/0022-3093(89)90031-8
Martin, Brigitte (1995) Keatite. II-Hydrothermal synthesis from silica-glass. European Journal of Mineralogy, 7 (6) 1389-1398 doi:10.1127/ejm/7/6/1389
Bieri-Gross, Barbara, Nesper, Reinhard (2011) Topological modeling of reconstructive phase transitions through periodic hyperbolic surfaces: the β-quartz to keatite type transition. Zeitschrift für Kristallographie, 226 (8). 670-677 doi:10.1524/zkri.2011.1383
Localities for Keatite
Showing 2 localities.
symbol to view information about a locality.
The Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
ⓘ - Click for references and further information on this occurrence.
? - Indicates mineral may be doubtful at this locality.
- Good crystals or important locality for species.
- World class for species or very significant.
(TL) - Type Locality for a valid mineral species.
(FRL) - First Recorded Locality for everything else (eg varieties).
All localities listed without proper references should be considered as questionable.
Kazakhstan | |
| Hill et al. (2013) |
Russia | |
| Kokh et al. (2023) |
