Silhydrite
A valid IMA mineral species
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About Silhydrite
Formula:
Si3O6 · H2O
Also written as 3SiO2 · H2O.
Colour:
White
Hardness:
1
Specific Gravity:
2.141
Crystal System:
Orthorhombic
Name:
Named for its composition: silicon plus water.
This page provides mineralogical data about Silhydrite.
Unique Identifiers
Mindat ID:
3658
Long-form identifier:
mindat:1:1:3658:6
IMA Classification of Silhydrite
Approved
Approval year:
1970
First published:
1972
Classification of Silhydrite
4.FM.30
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
F : Hydroxides (without V or U)
M : Hydroxides with H2O +- (OH); unclassified
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
F : Hydroxides (without V or U)
M : Hydroxides with H2O +- (OH); unclassified
75.2.4.1
75 : TECTOSILICATES Si Tetrahedral Frameworks
2 : Si Tetrahedral Frameworks - SiO2 with H2O and organics
75 : TECTOSILICATES Si Tetrahedral Frameworks
2 : Si Tetrahedral Frameworks - SiO2 with H2O and organics
7.8.7
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.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Shy | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Physical Properties of Silhydrite
Transparency:
Transparent
Colour:
White
Streak:
White
Hardness:
1 on Mohs scale
Fracture:
Irregular/Uneven, Sub-Conchoidal
Density:
2.141 g/cm3 (Measured) 2.116 g/cm3 (Calculated)
Optical Data of Silhydrite
Type:
Biaxial
Dispersion:
relatively weak
Chemistry of Silhydrite
Mindat Formula:
Si3O6 · H2O
Also written as 3SiO2 · H2O.
Also written as 3SiO2 · H2O.
Elements listed:
Common Impurities:
Ti,Al,Fe,Mg,Ca,Na,K,Cl,C
Crystallography of Silhydrite
Crystal System:
Orthorhombic
Cell Parameters:
a = 14.519(5) Å, b = 18.80(1) Å, c = 15.98(4) Å
Ratio:
a:b:c = 0.772 : 1 : 0.85
Unit Cell V:
4,361.86 ų (Calculated from Unit Cell)
Z:
28
Comment:
Point Group: n.d.; Space Group: n.d.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 14.50 Å | (100) |
| 3.424 Å | (82) |
| 3.143 Å | (35) |
| 3.627 Å | (27) |
| 3.540 Å | (25) |
| 7.31 Å | (22) |
| 7.07 Å | (21) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 10a: Neoproterozoic oxygenation/terrestrial biosphere | <0.6 |
| 48 : Soil leaching zone minerals | <0.6 |
Type Occurrence of Silhydrite
General Appearance of Type Material:
White, soft, microcrystalline massive material. Material is porous and will float on water briefly when dry (0.65 bulk density). Crystals less than 4 microns in size.
Place of Conservation of Type Material:
National Museum of Natural History (Smithsonian), Washington, D.C., USA, 125042.
USGS Denver Colorado.
USGS Denver Colorado.
Geological Setting of Type Material:
Spring deposit. Formed by leaching of sodium from magadiite from a cold, highly alkaline brine spring.
Also found in caves.
Also found in caves.
Associated Minerals at Type Locality:
Synonyms of Silhydrite
Other Language Names for Silhydrite
Common Associates
Associations Based on Photo Data:
Related Minerals - Strunz-mindat Grouping
| 4.FM. | Yttrotungstite-(Nd) | NdW2O7(OH) · H2O |
| 4.FM. | Charleshatchettite | CaNb4O10(OH)2 · 8H2O |
| 4.FM.15 | Franconite | Na(Nb2O5)(OH) · 3H2O |
| 4.FM.15 | Hochelagaite | (Ca,Na,Sr)(Nb,Ti,Si,Al)4O11 · 8H2O |
| 4.FM.15 | Ternovite | (Mg,Ca)Nb4O11 · nH2O |
| 4.FM.25 | Belyankinite | Ca1-2(Ti,Zr,Nb)5O12 · 9H2O (?) |
| 4.FM.25 | Gerasimovskite | Mn2+(Nb,Ti)5O12 · 9H2O (?) |
| 4.FM.25 | Manganbelyankinite | Mn2+(Ti,Nb)5O12 · 9H2O |
| 4.FM.35 | Cuzticite | Fe3+2(TeO6) · 3H2O |
| 4.FM.50 | Qatranaite | CaZn2(OH)6(H2O)2 |
| 4.FM.55 | 'Hydroplumbite' | 3PbO · H2O |
Other Information
Notes:
Insoluble in water
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 Silhydrite
mindat.org URL:
https://www.mindat.org/min-3658.html
Please feel free to link to this page.
Please feel free to link to this page.
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External Links:
Mineral Dealers:
References for Silhydrite
Reference List:
Gude 3d, Arthur J., Sheppard, Richard A. (1972) Silhydrite, 3SiO2·H2O, a new mineral from Trinity County, California. American Mineralogist, 57 (7-8). 1053-1065
Localities for Silhydrite
Showing 8 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.
Bolivia | |
| Abdelouas et al. (1995) |
USA | |
| Rogers et al. (1991) |
| Onac et al. (2011) | |
| Onac et al. (2011) | |
| Onac et al. (2011) | |
| Gude 3d et al. (1972) |
| webmineral.com (n.d.) +1 other reference |
| Rye et al. (2003) |
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Rome, Malheur County, Oregon, USA