Tridymite
A valid IMA mineral species - grandfathered
This page is currently not sponsored. Click here to sponsor this page.
About Tridymite
Formula:
SiO2
Colour:
Colourless, white, yellowish white, or grey
Lustre:
Vitreous
Hardness:
6½ - 7
Specific Gravity:
2.25 - 2.28
Crystal System:
Triclinic
Name:
From the Greek "Tridymos", triplet, alluding to its common twinning as trillings.
Type Locality:
Polymorph of:
Tridymite is a low pressure, mostly high-temperature-stable polymorph of silica that can also form or persist metastably at low temperatures. The high-temperature form occurs most notably as vapour-deposited, platey crystals in vesicles in some volcanic rocks, also rarely as phenocrysts in some felsic volcanics, or as a contact metamorphic material in some hornfels.
Tridymite can occur in seven polytypes and the most common at standard atmospheric pressure are known as α and β; both commensurately and incommensurately modulated structure variants are known. Below 100°C the triclinic form, α-tridymite is stable; there are also orthorhombic, monoclinic and hexagonal polytypes stable at higher temperatures. The orthorhombic β-tridymite polytype is most stable at elevated temperatures (>870°C) and it converts to β-cristobalite above 1470°C. However, tridymite does not usually form directly from pure β-quartz, and it is usually stabilised by alkali metals. Otherwise β-quartz transitions directly to cristobalite at 1050°C without the occurrence of the tridymite phase.
Some polytypes of tridymite ( from Deer et al. 2004)
In the above table, M, O, H, C, P, L and S stand for monoclinic, orthorhombic, hexagonal, centered, primitive, low (temperature) and superlattice. T indicates the temperature, at which the corresponding phase is relatively stable, though the interconversions between phases are complex and sample dependent, and all these forms can coexist at ambient conditions. Mineralogy handbooks often arbitrarily assign tridymite to the triclinic crystal system, yet use hexagonal Miller indices because of the hexagonal crystal shape.
A low temperature form is commonly reported as a constituent of certain types of opal, intergrown with cristobalite (opal-CT), found in many environments including marine sedimentary rocks derived from biogenic opaline sediments, and low temperature cavity infillings, replacements, etc., including some precious opal (Sanders, 1975). Some wood opal is mostly tridymite (Mitchell & Tufts, 1973). However, some workers note that opal is hydrous and lacks any long-range ordering, the opal structure just mimicking cristobalite and tridymite, so may not contain true tridymite (Smith, 1998).
Large tridymite deposits have been detected on Mars, but their nature and origin are uncertain (Lakdawalla, 2015).
Tridymite can occur in seven polytypes and the most common at standard atmospheric pressure are known as α and β; both commensurately and incommensurately modulated structure variants are known. Below 100°C the triclinic form, α-tridymite is stable; there are also orthorhombic, monoclinic and hexagonal polytypes stable at higher temperatures. The orthorhombic β-tridymite polytype is most stable at elevated temperatures (>870°C) and it converts to β-cristobalite above 1470°C. However, tridymite does not usually form directly from pure β-quartz, and it is usually stabilised by alkali metals. Otherwise β-quartz transitions directly to cristobalite at 1050°C without the occurrence of the tridymite phase.
Some polytypes of tridymite ( from Deer et al. 2004)
|
In the above table, M, O, H, C, P, L and S stand for monoclinic, orthorhombic, hexagonal, centered, primitive, low (temperature) and superlattice. T indicates the temperature, at which the corresponding phase is relatively stable, though the interconversions between phases are complex and sample dependent, and all these forms can coexist at ambient conditions. Mineralogy handbooks often arbitrarily assign tridymite to the triclinic crystal system, yet use hexagonal Miller indices because of the hexagonal crystal shape.
A low temperature form is commonly reported as a constituent of certain types of opal, intergrown with cristobalite (opal-CT), found in many environments including marine sedimentary rocks derived from biogenic opaline sediments, and low temperature cavity infillings, replacements, etc., including some precious opal (Sanders, 1975). Some wood opal is mostly tridymite (Mitchell & Tufts, 1973). However, some workers note that opal is hydrous and lacks any long-range ordering, the opal structure just mimicking cristobalite and tridymite, so may not contain true tridymite (Smith, 1998).
Large tridymite deposits have been detected on Mars, but their nature and origin are uncertain (Lakdawalla, 2015).
Unique Identifiers
Mindat ID:
4015
Long-form identifier:
mindat:1:1:4015:6
GUID
(UUID V4):
(UUID V4):
a6690284-91bd-4ecf-a045-8f91efc49d49
IMA Classification of Tridymite
Approved, 'Grandfathered' (first described prior to 1959)
First published:
1868
Classification of Tridymite
4.DA.10
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
75.1.2.1
75 : TECTOSILICATES Si Tetrahedral Frameworks
1 : Si Tetrahedral Frameworks - SiO2 with [4] coordinated Si
75 : TECTOSILICATES Si Tetrahedral Frameworks
1 : Si Tetrahedral Frameworks - SiO2 with [4] coordinated Si
7.8.3
7 : Oxides and Hydroxides
8 : Oxides of Si
7 : Oxides and Hydroxides
8 : Oxides of Si
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
Symbol | Source | Reference |
---|---|---|
Trd | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Trd | Kretz (1983) | Kretz, R. (1983) Symbols of rock-forming minerals. American Mineralogist, 68, 277–279. |
Trd | Siivolam & Schmid (2007) | Siivolam, J. and Schmid, R. (2007) Recommendations by the IUGS Subcommission on the Systematics of Metamorphic Rocks: List of mineral abbreviations. Web-version 01.02.07. IUGS Commission on the Systematics in Petrology. download |
Trd | Whitney & Evans (2010) | Whitney, D.L. and Evans, B.W. (2010) Abbreviations for names of rock-forming minerals. American Mineralogist, 95, 185–187 doi:10.2138/am.2010.3371 |
Trd | The Canadian Mineralogist (2019) | The Canadian Mineralogist (2019) The Canadian Mineralogist list of symbols for rock- and ore-forming minerals (December 30, 2019). download |
Trd | Warr (2020) | Warr, L.N. (2020) Recommended abbreviations for the names of clay minerals and associated phases. Clay Minerals, 55, 261–264 doi:10.1180/clm.2020.30 |
Physical Properties of Tridymite
Vitreous
Transparency:
Transparent, Translucent
Comment:
May be pearly on {0001}
Colour:
Colourless, white, yellowish white, or grey
Streak:
White
Hardness:
6½ - 7 on Mohs scale
Tenacity:
Brittle
Cleavage:
Poor/Indistinct
[0001] Indistinct, [1010] Imperfect
[0001] Indistinct, [1010] Imperfect
Fracture:
Conchoidal
Density:
2.25 - 2.28 g/cm3 (Measured) 2.28 g/cm3 (Calculated)
Optical Data of Tridymite
Type:
Biaxial (+)
RI values:
nα = 1.468 - 1.482 nβ = 1.470 - 1.484 nγ = 1.474 - 1.486
2V:
Measured: 40° to 86°, Calculated: 50° to 72°
Max Birefringence:
δ = 0.006
Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
and does not take into account mineral colouration.
Surface Relief:
Moderate
Dispersion:
none
Chemistry of Tridymite
Mindat Formula:
SiO2
Elements listed:
Crystallography of Tridymite
Crystal System:
Triclinic
Class (H-M):
1 - Pedial
Cell Parameters:
a = 9.932(5) Å, b = 17.216(6) Å, c = 81.854(9) Å
α = 90°, β = 90°, γ = 90°
α = 90°, β = 90°, γ = 90°
Ratio:
a:b:c = 0.577 : 1 : 4.755
Unit Cell V:
13,996.16 ų (Calculated from Unit Cell)
Z:
320
Morphology:
Pseudohexagonal plates, wedge-shaped, tabular.
Twinning:
Trilling, multiple contact twins or simple twins on {1016} and contact or penetration twins on {3034}
Comment:
Orthorhombic, pseudohexagonal; triclinic below 100°C
Crystallographic forms of Tridymite
Crystal Atlas:
Image Loading
3d models and HTML5 code kindly provided by
www.smorf.nl.
Toggle
Edge Lines | Miller Indices | Axes
Transparency
Opaque | Translucent | Transparent
View
Along a-axis | Along b-axis | Along c-axis | Start rotation | Stop rotation
Toggle
Edge Lines | Miller Indices | Axes
Transparency
Opaque | Translucent | Transparent
View
Along a-axis | Along b-axis | Along c-axis | Start rotation | Stop rotation
Crystal Structure
Load
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Show
Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
Remove metal-metal sticks
Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
Remove metal-metal sticks
Display Options
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
View
CIF File Best | x | y | z | a | b | c
CIF File Best | x | y | z | a | b | c
Rotation
Stop | Start
Stop | Start
Labels
Console Off | On | Grey | Yellow
Console Off | On | Grey | Yellow
Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure
ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
---|---|---|---|---|---|---|---|
0000531 | Tridymite | Dollase W A, Baur W H (1976) The superstructure of meteoritic low tridymite solved by computer simulation American Mineralogist 61 971-978 | 1976 | Steinbach meteorite, Saxony, Germany | 0 | 293 | |
0006615 | Tridymite | Graetsch H, Topalovic-Dierdorf I (1996) 29Si MAS NMR spectrum and superstructure of modulated tridymite L3-To(MX-1) European Journal of Mineralogy 8 103-113 | 1996 | synthetic | 0 | 293 | |
0006616 | Tridymite | Graetsch H, Topalovic-Dierdorf I (1996) 29Si MAS NMR spectrum and superstructure of modulated tridymite L3-To(MX-1) European Journal of Mineralogy 8 103-113 | 1996 | synthetic | 0 | 293 | |
0008552 | Tridymite | Graetsch H (2001) X-ray powder diffraction study on the modulated high temperature forms of SiO2 tridymite between 110 and 220 C Physics and Chemistry of Minerals 28 313-321 | 2001 | synthetic | 0 | 293 | |
0008553 | Tridymite | Graetsch H (2001) X-ray powder diffraction study on the modulated high temperature forms of SiO2 tridymite between 110 and 220 C Physics and Chemistry of Minerals 28 313-321 | 2001 | synthetic | 0 | 388 | |
0020733 | Tridymite | Dollase W A (1967) The crystal structure at 220 C of orthothombic high tridymite from the Steinbach meteorite Acta Crystallographica 23 617-623 | 1967 | Steinbach meteorite | 0 | 293 | |
0020734 | Tridymite | Kato V K, Nukui A (1976) Die kristallstruktur des monoklinen tief-tridymits Acta Crystallographica B32 2486-2491 | 1976 | synthetic | 0 | 293 | |
0009625 | Tridymite | Konnert J H, Appleman D E (1978) The crystal structure of low tridymite Acta Crystallographica B34 391-403 | 1978 | Plumas County, California, USA | 0 | 293 | |
0020744 | Tridymite | Lee S, Xu H (2019) Using powder XRD and pair distribution function to determine anisotropic atomic displacement parameters of orthorhombic tridymite and tetragonal cristobalite Acta Crystallographica B75 https://doi.org/10.1107/S2052520619000933 | 2019 | rhyolitic rock, New Mexico, USA | 0 | 293 | |
0013132 | Tridymite | Hirose T, Kihara K, Okuno M, Fujinami S, Shinoda K (2005) X-ray, DTA and Raman studies of monoclinic tridymite and its higher temperature orthorhombic modification with varying temperature. Journal of Mineralogical and Petrological Sciences 100 55-69 | 2005 | synthetic | 0 | 298 | |
0013133 | Tridymite | Hirose T, Kihara K, Okuno M, Fujinami S, Shinoda K (2005) X-ray, DTA and Raman studies of monoclinic tridymite and its higher temperature orthorhombic modification with varying temperature. Journal of Mineralogical and Petrological Sciences 100 55-69 | 2005 | synthetic | 0 | 373 | |
0013134 | Tridymite | Hirose T, Kihara K, Okuno M, Fujinami S, Shinoda K (2005) X-ray, DTA and Raman studies of monoclinic tridymite and its higher temperature orthorhombic modification with varying temperature. Journal of Mineralogical and Petrological Sciences 100 55-69 | 2005 | synthetic | 0 | 413 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
d-spacing | Intensity |
---|---|
4.30 Å | (100) |
4.09 Å | (90) |
3.80 Å | (60) |
3.249 Å | (30) |
2.964 Å | (16) |
2.483 Å | (16) |
2.305 Å | (8) |
Geological Environment
Paragenetic Mode(s):
Paragenetic Mode | Earliest Age (Ga) |
---|---|
Stage 1: Primary nebular phases | 4.567-4.561 |
4 : Primary chondrule phases | 4.566–4.561 |
Stage 2: Planetesimal differentiation and alteration | 4.566-4.550 |
5 : Primary asteroid phases | 4.566–4.560 |
Stage 3a: Earth’s earliest Hadean crust | >4.50 |
9 : Lava/xenolith minerals (hornfels, sanidinite facies) | |
10 : Basalt-hosted zeolite minerals | |
Stage 4a: Earth’s earliest continental crust | >4.4-3.0 |
20 : Acidic volcanic rocks | |
Near-surface Processes | |
26 : Hadean detrital minerals | |
Stage 10a: Neoproterozoic oxygenation/terrestrial biosphere | <0.6 |
50 : Coal and/or oil shale minerals | <0.36 |
Stage 10b: Anthropogenic minerals | <10 Ka |
54 : Coal and other mine fire minerals (see also #51 and #56) |
Geological Setting:
Vapor phase deposition in vesicles and lithophysae, phenocrysts in volcanic rocks, contact metamorphosed sandstones.
Type Occurrence of Tridymite
Reference:
vom Rath, G. (1868) Vorläufige Mitteilung über eine neue Kristallform der Kieselsäure (Tridymit). Annalen der Physik und Chemie: 209: 507.
Synonyms of Tridymite
Other Language Names for Tridymite
Varieties of Tridymite
Christensenite | Name given to a solid solution of 5 % NaAlSiO4 in tridymite from a lava at Deception Island, Western Antartica found during the Norwegian Antartic expeditions 1927-1928. |
Common Associates
Associated Minerals Based on Photo Data:
228 photos of Tridymite associated with Hematite | Fe2O3 |
85 photos of Tridymite associated with Phlogopite | KMg3(AlSi3O10)(OH)2 |
77 photos of Tridymite associated with Fayalite | Fe2+2SiO4 |
70 photos of Tridymite associated with Pseudobrookite | Fe2TiO5 |
61 photos of Tridymite associated with Enstatite | Mg2Si2O6 |
45 photos of Tridymite associated with Titanite | CaTi(SiO4)O |
38 photos of Tridymite associated with Magnetite | Fe2+Fe3+2O4 |
36 photos of Tridymite associated with Augite | (CaxMgyFez)(Mgy1Fez1)Si2O6 |
34 photos of Tridymite associated with Edenite | NaCa2Mg5(Si7Al)O22(OH)2 |
32 photos of Tridymite associated with Cristobalite | SiO2 |
Related Minerals - Strunz-mindat Grouping
4.DA. | Chibaite | SiO2 · n(CH4, C2H6, C3H8, i-C4H10) (n = 3/17 (max)) |
4.DA. | Carbon Dioxide Ice | CO2 |
4.DA. | Bosoite | SiO2 · nCxH2x+2 |
4.DA.05 | Quartz | 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.40 | Stishovite | SiO2 |
4.DA.45 | Keatite | SiO2 |
4.DA.50 | Seifertite | SiO2 |
4.DA.55 | Quartz-beta | SiO2 |
Other Information
Thermal Behaviour:
High tridymite or β-tridymite forms between 870 and 1470°C.
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 Tridymite
mindat.org URL:
https://www.mindat.org/min-4015.html
Please feel free to link to this page.
Please feel free to link to this page.
Search Engines:
External Links:
Mineral Dealers:
References for Tridymite
Reference List:
Cressey, G. (2004) W.A. Deer, R.A. Howie, W.S. Wise and J. Zussman. Rock-Forming Minerals. Volume 4B. Second Edition. Framework Silicates: Silica Minerals, Feldspathoids and the Zeolites.
London (The Geological Society) 2004, xv + 982 pp. £125 (£62.50 to GSL members) ISBN 1-86239-144-0. Hardback. Mineralogical Magazine, 68 (5) 831-832 doi:10.1180/0680831p.22
Localities for Tridymite
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).
Struck out - Mineral was erroneously reported from this locality.
Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).
All localities listed without proper references should be considered as questionable.
All localities listed without proper references should be considered as questionable.
Antarctica | |
| |
| |
| |
| |
| |
Argentina | |
| |
| |
Australia | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
Austria | |
| |
| |
| |
| |
| |
| |
| |
| |
Azerbaijan | |
| |
Bangladesh | |
| |
Belarus | |
| |
Belgium | |
| |
Bolivia | |
| |
Brazil | |
| |
| |
| |
| |
Burundi | |
| |
Canada | |
| |
| |
Chile | |
| |
China | |
| |
| |
| |
| |
| |
Costa Rica | |
| |
Czech Republic | |
| |
| |
| |
Ecuador | |
| |
El Salvador | |
| |
Equatorial Guinea | |
| |
Estonia | |
| |
Faroe Islands | |
| |
Finland | |
| |
| |
| |
France | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
Georgia | |
| |
Germany | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
Greece | |
| |
| |
| |
Greenland | |
| |
Hungary | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
Iceland | |
| |
India | |
| |
| |
Indonesia | |
| |
| |
| |
Iran | |
| |
Israel | |
| |
Italy | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
Japan | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
Jordan | |
| Galuskin, Evgeny V., Stachowicz, Marcin, Galuskina, Irina O., Woźniak, Krzysztof, Vapnik, Yevgeny, Murashko, Mikhail N., Zieliński, Grzegorz (2023) Deynekoite, Ca9Fe3+(PO4)7 – a new mineral of the merrillite group from phosphide-bearing contact facies of paralava, Hatrurim Complex, Daba-Siwaqa, Jordan. Mineralogical Magazine, 1-31 doi:10.1180/mgm.2023.71 |
Kenya | |
| |
Lebanon | |
| |
Lithuania | |
| |
Madagascar | |
| |
| |
Malawi | |
| |
Mauritania | |
| |
Mexico | |
| |
| |
| |
| |
| |
| |
| |
| |
Middle East | |
Mongolia | |
| |
Morocco | |
| Rolf LuetckeIdentified by Rolf Luetcke: Visual Identification |
Namibia | |
| |
| |
Netherlands | |
| |
| |
New Zealand | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
Nicaragua | |
| |
Nigeria | |
| |
Northwest Africa Meteorites | |
Oman | |
| |
Pakistan | |
| |
| |
Panama | |
Papua New Guinea | |
| |
| |
Peru | |
| |
Philippines | |
| |
Poland | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
Portugal | |
| |
| |
| CEDOMIdentified by Michele Dondi: XRD |
| |
Romania | |
| |
| |
| |
Russia | |
| |
| |
| |
| |
| |
| |
| Zhitova, Elena S., Khanin, Dmitry A., Nuzhdaev, Anton A., Nazarova, Maria A., Ismagilova, Rezeda M., Shilovskikh, Vladimir V., Kupchinenko, Anastasia N., Kuznetsov, Ruslan A., Zhegunov, Pavel S. (2022) Efflorescent Sulphates with M+ and M2+ Cations from Fumarole and Active Geothermal Fields of Mutnovsky Volcano (Kamchatka, Russia) Minerals, 12 (5) 600 doi:10.3390/min12050600 |
| |
| |
| |
| |
| |
| |
| Khomyakov, A. P., Nechelyustov, G. N., Sokolova, E., Bonaccorsi, E., Merlino, S., Pasero, M. (2002) Megakalsilite, a new polymorph of KAlSiO4 from the Khibina Alkaline Massif, Kola Peninsula, Russia: mineral description and crystal structure. The Canadian Mineralogist, 40 (3) 961-970 doi:10.2113/gscanmin.40.3.961 |
| |
| |
| |
| |
| |
| |
| |
Saudi Arabia | |
| |
Slovakia | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
South Africa | |
| |
| |
| |
South Sudan | |
| |
Spain | |
| |
| |
| |
| |
| |
| |
Tajikistan | |
| |
Tunisia | |
Turkey | |
| |
| |
UK | |
| |
| |
| |
| |
Ukraine | |
| |
USA | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| Douglas Merson collectionIdentified by Douglas Merson: Visual Identification, Inferred (explain how) |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
Vanuatu | |
| |
Mars | |
| |
Northwest Africa Meteorites | |
The Moon | |
| |
| |
Quick NavTopAbout TridymiteUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography Crystallographic forms Crystal StructureX-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesVarietiesCommon AssociatesStrunz-MindatOther InformationInternet Links References Localities Locality List
Caspar quarry, Ettringen, Vordereifel, Mayen-Koblenz, Rhineland-Palatinate, Germany