Silhydrite Mineral Data

General Silhydrite Information

Chemical Formula:

3SiO2•(H2O)

Composition:

Molecular Weight = 198.27 gm

Silicon 42.50 % Si 90.91 % SiO₂

Hydrogen 1.02 % H 9.09 % H₂O

Oxygen 56.49 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

3(SiO₂)•(H₂O)

Environment:

Leached magadiite.

IMA Status:

Approved IMA 1972

Locality:

Trinity County magadiite locality, 6 miles east of Trinity Center Trinity Co., California. Link to MinDat.org Location Data.

Name Origin:

Named for its composition, a silica hydrate.

Name Pronunciation:

Silhydrite + Pronunciation

Silhydrite Image

Images:

Silhydrite

Comments: Fine grained massive silhydrite.
Location: Near Rome, Oregon, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Silhydrite Crystallography

Axial Ratios:

a:b:c =0.7722:1:0.8477

Cell Dimensions:

a = 14.519, b = 18.8, c = 15.938, Z = 28; V = 4,350.39 Den(Calc)= 2.12

Crystal System:

Orthorhombic Space Group: P???

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 14.5(1), 3.424(0.82), 3.143(0.35),

Physical Properties of Silhydrite

Color:

White.

Density:

2.141

Fracture:

Sub Conchoidal - Fractures developed in brittle materials characterized by semi-curving surfaces.

Habit:

Massive - Uniformly indistinguishable crystals forming large masses.

Hardness:

1 - Talc

Streak:

white

Optical Properties of Silhydrite

Gladstone-Dale:

CI meas= 0.011 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.001 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2198,KPDmeas= 0.2177,KC= 0.22
Ncalc = 1.47

Optical Data:

Biaxial (?), b=1.466

Calculated Properties of Silhydrite

Electron Density:

Bulk Density (Electron Density)=2.14 gm/cc
note: Specific Gravity of Silhydrite =2.12 gm/cc.

Fermion Index:

Fermion Index = 0.02
Boson Index = 0.98

Photoelectric:

PE_Silhydrite= 1.65 barns/electron
U=PE_Silhydrite x rElectron Density= 3.54 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Silhydrite is Not Radioactive

Silhydrite Classification

Dana Class:

75.02.04.01 (75)Tectosilicate Si Tetrahedral Frameworks

(75.02)SiO2 with H2O and organics

(75.02.04)Dana Group

75.02.04.01 Silhydrite 3SiO2•(H2O) P??? Ortho

Strunz Class:

04.FM.30 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate

04.F - Hydroxides (without V or U)

04.FM -Hydroxides with H2O ï¿½ (OH); Unclassified

04.FM.30 Silhydrite 3SiO2•(H2O) P??? Ortho

Other Silhydrite Information

References:

NAME( MinRec) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Silhydrite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - GeoScienceWorld
6 - Google Images
7 - Google Scholar
8 - Handbook of Mineralogy (MinSocAm)
9 - Handbook of Mineralogy (UofA)
10 - MinDAT
11 - Mineralienatlas (Deutsch)
12 - Online Mineral Museum
13 - QUT Mineral Atlas
14 - Ruff.Info

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Print or Cut-and-Paste your Silhydrite Specimen Label here :

Silhydrite

3SiO2•(H2O)
Dana No: 75.02.04.01 Strunz No: 04.FM.30
Locality:

Notes:

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