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Vermiculite Mineral Data

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General Vermiculite Information

Help on Chemical  Formula: Chemical Formula: (Mg,Fe++,Al)3(Al,Si)4O10(OH)2•4(H2O)
Help on Composition: Composition: Molecular Weight = 504.19 gm
   Magnesium   8.68 %  Mg   14.39 % MgO
   Aluminum   23.01 %  Al   43.48 % Al2O3
   Iron        9.97 %  Fe   12.82 % FeO
   Silicon     5.57 %  Si   11.92 % SiO2
   Hydrogen    2.00 %  H    17.87 % H2O
   Oxygen     50.77 %  O
             ______        ______ 
             100.00 %      100.48 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Mg1.8Fe2+0.9Al4.3SiO10(OH)2•4(H2O)
Help on Environment: Environment: Appears to have been formed by weathering or hydrothermal alteration of iron-bearing phlogopite an annite.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1824
Help on Locality: Locality: Millbury, Worchaster County, MA, USA Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: From the Latin vermiculus, "little worm."
Help on Name Pronunciation: Name Pronunciation: Vermiculite + Pronunciation Say VERMICULITE
Help on Synonym: Synonym: Batavite - Fe-poor variety of vermiculite

Vermiculite Image

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Comments: Micaceous vermiculite book.
Location: Brinton's Quarry, near West Chester, Chester County, Pennsylvania, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Vermiculite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.5698:1:1.6218
Help on Cell Dimensions: Cell Dimensions: a = 5.26, b = 9.23, c = 14.97, Z = 2; beta = 96.82° V = 721.65 Den(Calc)= 2.32
Help on Crystal System: Crystal System: Monoclinic - Prismatic H-M Symbol (2/m) Space Group: C 2/m

Physical Properties of Vermiculite

Help on Cleavage: Cleavage: {001} Perfect
Help on Color: Color: Colorless, Green, Gray white, Yellow brown.
Help on Density: Density: 2.3 - 2.7, Average = 2.5
Help on Diaphaneity: Diaphaneity: Translucent
Help on Fracture: Fracture: Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern.
Help on Habit: Habit: Lamellar - Thin laminae producing a lamellar structure.
Help on Habit: Habit: Scaly - Morphology like fish scales.
Help on Hardness: Hardness: 1.5-2 - Talc-Gypsum
Help on Luster: Luster: Vitreous - Dull
Help on Streak: Streak: greenish white

Optical Properties of Vermiculite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.026 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= -0.05 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2398,KPDmeas= 0.2225,KC= 0.2284
Ncalc = 1.53 - 1.62
Help on Optical Data: Optical Data: Biaxial (-), a=1.525-1.561, b=1.545-1.581, g=1.545-1.581, bire=0.0200, 2V(Calc)=0, 2V(Meas)=0-8. Dispersion weak, r > v.
Help on Pleochroism (x): Pleochroism (x): colorless or pale green.
Help on Pleochroism (y): Pleochroism (y): pale brown, yellowish green, or brownish green.
Help on Pleochroism (z): Pleochroism (z): pale brown, yellowish green, or brownish green.

Calculated Properties of Vermiculite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.51 gm/cc
note: Specific Gravity of Vermiculite =2.50 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.01
Boson Index = 0.99
Help on Photoelectric: Photoelectric: PEVermiculite = 4.01 barns/electron
U=PEVermiculite x rElectron Density= 10.06 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Vermiculite is Not Radioactive

Vermiculite Classification

Help on  Dana Class: Dana Class: 71.02.02d.03 (71)Phyllosilicate Sheets of Six-Membered Rings
  (71.02)with 2:1 Layers
  (71.02.02d)Mica Group (Hydromica subgroup)
71.02.02d.01 Hydrobiotite [K(Mg,Fe)3(Al,Fe)Si3O10(OH,F)2]•[(Mg,Fe,Al)3(Si,Al)4O10(OH)2•4(H2O)] C 2/m 2/m
71.02.02d.02 Illite* (K,H3O)(Al,Mg,Fe)2(Si,Al)4O10[(OH)2,(H2O)] C 2/m 2/m
71.02.02d.03 Vermiculite (Mg,Fe,Al)3(Al,Si)4O10(OH)2•4(H2O) C 2/m 2/m
71.02.02d.04 Brammallite* (Na,H3O)(Al,Mg,Fe)2(Si,Al)4O10[(OH)2,(H2O)] C 2/c 2/m
Help on  Strunz Class: Strunz Class: 09.EC.50 09 - SILICATES (Germanates)
  09.E - Phyllosilicates
  09.EC -Phyllosilicates with mica sheets, composed of tetrahedral and octahedral nets
09.EC.50 Vermiculite (Mg,Fe,Al)3(Al,Si)4O10(OH)2•4(H2O) C 2/m 2/m

Other Vermiculite Information

Help on References: References: NAME( Duda&Rejl90) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Heinrich65)
Help on See Also: See Also: Links to other databases for Vermiculite :
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

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Dana No: 71.02.02d.03 Strunz No: 09.EC.50





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