General Montmorillonite Information Chemical Formula: |
(Na,Ca)0,3(Al,Mg)2Si4O10(OH)2•n(H2O) |
Composition: |
Molecular Weight = 549.07 gm |
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Sodium 0.84 % Na 1.13 % Na2O |
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Calcium 0.73 % Ca 1.02 % CaO |
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Aluminum 9.83 % Al 18.57 % Al2O3 |
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Silicon 20.46 % Si 43.77 % SiO2 |
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Hydrogen 4.04 % H 36.09 % H2O |
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Oxygen 64.11 % O |
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100.00 % 100.58 % = TOTAL OXIDE |
Empirical Formula: |
Na0.2Ca0.1Al2Si4O10(OH)2(H2O)10 |
IMA Status: |
Valid Species (Pre-IMA) 1847 |
Locality: |
Veinne, Montmorillone, France. Link to MinDat.org Location Data. |
Name Origin: |
Named after the locality. |
Name Pronunciation: |
Montmorillonite + Pronunciation |
Synonym: |
Bentonite |
| | Montmorillonite Image
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Montmorillonite Crystallography Axial Ratios: |
a:b:c =0.5782:1:1.1129 |
Cell Dimensions: |
a = 5.17, b = 8.94, c = 9.95, Z = 1; beta = 99.9° V = 453.04 Den(Calc)= 2.01 |
Crystal System: |
Monoclinic - PrismaticH-M Symbol (2/m) Space Group: C 2/m |
Crystal Structure:
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Mouse
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| Physical Properties of Montmorillonite Cleavage: |
{001} Perfect |
Color: |
White, Gray white, Yellow, Brownish yellow, Greenish yellow. |
Density: |
2 - 2.7, Average = 2.35 |
Diaphaneity: |
Translucent to Opaque |
Fracture: |
Earthy - Dull, clay-like fractures with no visible crystalline affinities, (e.g. howlite). |
Habit: |
Earthy - Dull, clay-like texture with no visible crystalline affinities, (e.g. howlite). |
Hardness: |
1.5-2 - Talc-Gypsum |
Luminescence: |
Non-fluorescent. |
Luster: |
Earthy (Dull) |
Streak: |
white |
| Optical Properties of Montmorillonite Gladstone-Dale: |
CI meas= 0.135 (Poor) - where the CI = (1-KPDmeas/KC) |
CI calc= -0.012 (Superior) - where the CI = (1-KPDcalc/KC) KPDcalc= 0.2595,KPDmeas= 0.2219,KC= 0.2565 Ncalc = 1.51 - 1.69 Optical Data: |
Biaxial (-), a=1.485-1.535, b=1.504-1.55, g=1.505-1.55, bire=0.0150-0.0200, 2V(Calc)=0-24, 2V(Meas)=5-30. Dispersion none. |
Pleochroism (x): |
colorless. |
Pleochroism (y): |
colorless. |
Pleochroism (z): |
colorless. |
| Calculated Properties of Montmorillonite Electron Density: |
Bulk Density (Electron Density)=2.08 gm/cc |
note: Specific Gravity of Montmorillonite =2.01 gm/cc. Fermion Index: |
Fermion Index = 0.0098785928 |
Boson Index = 0.9901214072 Photoelectric: |
PEMontmorillonite = 1.26 barns/electron |
U=PEMontmorillonite x rElectron Density= 2.63 barns/cc. Radioactivity: |
GRapi = 0 (Gamma Ray American Petroleum Institute Units) |
Montmorillonite is Not Radioactive | Montmorillonite Classification Dana Class: |
71.03.01a.02 (71)Phyllosilicate Sheets of Six-Membered Rings |
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(71.03)with 2:1 clays |
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(71.03.01a)Smectite group (Dioctahedral Smectites) |
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Strunz Class: |
09.EC.40 09 - SILICATES (Germanates) |
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09.E - Phyllosilicates |
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09.EC -Phyllosilicates with mica sheets, composed of tetrahedral and octahedral nets |
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| Other Montmorillonite Information References: |
NAME( Duda&Rejl90) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Heinrich65) |
See Also: |
Links to other databases for Montmorillonite : |
1 - Alkali-Nuts(English) 2 - Alkali-Nuts(Francais) 3 - Am. Min. Crystal Structure Database 4 - Amethyst Galleries' Mineral Gallery 5 - Athena 6 - EUROmin Project 7 - Ecole des Mines de Paris 8 - GeoScienceWorld 9 - Google Images 10 - Google Scholar 11 - Handbook of Mineralogy (MinSocAm) 12 - Handbook of Mineralogy (UofA) 13 - MinDAT 14 - Mineralienatlas (Deutsch) 15 - Online Mineral Museum 16 - QUT Mineral Atlas 17 - Ruff.Info 18 - Scandinavian mineral gallery Search for Montmorillonite using: Visit our Advertisers for Montmorillonite : A Bijoux Google Search for MontmorilloniteAdam's Minerals Google Search for Montmorillonite Cape Minerals Google Search for Montmorillonite Dakota Matrix Minerals Google Search for Montmorillonite Excalibur Mineral Corp. Google Search for Montmorillonite Exceptional Minerals Google Search for Montmorillonite John Betts Fine Minerals Search for Montmorillonite McDougall Minerals Google Search for Montmorillonite Mineral News Website Link Rock and Mineral Shows Google Search for Montmorillonite Weinrich Minerals, Inc. Google Search for Montmorillonite Ask about Montmorillonite here : Print or Cut-and-Paste your Montmorillonite Specimen Label here :
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