Vermiculite Mineral Data

Vermiculite Mineral Data +

[What's New] [Mineral Galleries] [About Us] [Contacts] [Login]
At AA Mineral Specimens, we source quality Mineral Specimens, Fossils, Gemstones,
Decorative Stones, Lapidary Material and Specimen Sets world-wide

General Vermiculite Information

Chemical Formula:

(Mg,Fe++,Al)3(Al,Si)4O10(OH)2·4(H2O)

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

Empirical Formula:

Mg_1.8Fe²⁺_0.9Al_4.3SiO₁₀(OH)₂·4(H₂O)

IMA Status:

Valid Species (Pre-IMA) 1824

Locality:

Link to MinDat.org Location Data.

Name Origin:

From the Latin vermiculus, "little worm."

Vermiculite Image

Images:

Vermiculite

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

Axial Ratios:

a:b:c =0.5698:1:1.6218

Cell Dimensions:

a = 5.26, b = 9.23, c = 14.97, Z = 2; beta = 96.82° V = 721.65 Den(Calc)= 2.32

Crystal System:

Monoclinic - PrismaticH-M Symbol (2/m) Space Group: C 2/m

Crystal Structure:

Mouse
drag1 - LMB Manipulate Structure
drag2 - RMB Resize/Rotate
Keyboard
S - Stereo Pair on/off
H - Help Screen
I - Data Info
A - Atoms On/Off
P - Polyhedra On/Off
B - Bonds On/Off
Help on Above

Gruner J W , American Mineralogist , 19 (1934) p.557-575, The structures of vermiculites and their collapse by dehydration

View Additional jPOWD Structure files for Vermiculite
[1] [2] [3] [4] [5]

Physical Properties of Vermiculite

Cleavage:

[001] Perfect

Color:

Colorless, Green, Gray white, Yellow brown.

Density:

2.3 - 2.7, Average = 2.5

Diaphaniety:

Translucent

Fracture:

Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern.

Habit:

Lamellar - Thin laminae producing a lamellar structure.

Habit:

Scaly - Morphology like fish scales.

Hardness:

1.5-2 - Talc-Gypsum

Luster:

Vitreous - Dull

Streak:

greenish white

Optical Properties of Vermiculite

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

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.

Pleochroism (x):

colorless or pale green.

Pleochroism (y):

pale brown, yellowish green, or brownish green.

Pleochroism (z):

pale brown, yellowish green, or brownish green.

Calculated Properties of Vermiculite

Electron Density:

r_electron=2.51 gm/cc
note: r_Vermiculite=2.50 gm/cc.

Fermion Index

Fermion Index = 0.01363
Boson Index = 0.98637

Photoelectric:

PE_Vermiculite= 4.01 barns/electron
U=PE_Vermiculite x r_electron= 10.06 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)

Vermiculite is Not Radioactive

Vermiculite Classification

Dana Class:

71.2.2d.3 (71)Phyllosilicate Sheets of Six-Membered Rings

(71.2)with 2:1 Layers

(71.2.2d)Mica Group (Hydromica subgroup)

71.2.2d.1 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

71.2.2d.2 Illite* (K,H3O)(Al,Mg,Fe)2(Si,Al)4O10[(OH)2,(H2O)] C 2/m 2/m

71.2.2d.3 Vermiculite (Mg,Fe,Al)3(Al,Si)4O10(OH)2·4(H2O) C 2/m 2/m

71.2.2d.4 Brammallite* (Na,H3O)(Al,Mg,Fe)2(Si,Al)4O10[(OH)2,(H2O)] C 2/c 2/m

Strunz Class:

VIII/H.21-10 VIII - Silicates

VIII/H - Phyllosilicates (layered) Mica like with [Si4O10]4- and related groups

VIII/H.21 - Vermiculite series

VIII/H.21-10 Vermiculite (Mg,Fe,Al)3(Al,Si)4O10(OH)2·4(H2O) C 2/m 2/m

Other Vermiculite Information

References:

NAME( Duda&Rejl90) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Heinrich65)

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 - Google Images
9 - Google Scholar
10 - Handbook of Mineralogy (MinSocAm)
11 - Handbook of Mineralogy (UofA)
12 - MinDAT
13 - MinMax(Deutsch)
14 - MinMax(English)
15 - Mineralienatlas (Deutsch)
16 - QUT Mineral Atlas
17 - Ruff.Info
18 - Scandinavian mineral gallery
19 - WWW-MINCRYST

Search for Vermiculite using:

[ALTAVISTA] [AOL] [All-The-Web] [HotBot] [Ixquick] [MAMMA] [MSN.COM] [Netscape] [Scirus] [Teoma] [Wikipedia] [YAHOO]

Visit our Advertisers for Vermiculite :

AA Mineral Specimens

B & L Fine Minerals

Dan Weinrich Fine Minerals

Dan Weinrich Auctions

John Betts Fine Minerals

Mason's Minerals

Mineral News

Mineral of the Month Club

MineralsWeb Fine Minerals

The GeoZone

Wrights Rock Shop

Translate Vermiculite Mineral Data :

Ask about Vermiculite here :
Ask-A-Mineralogist from the Mineralogical Society of America
Mindat.org's Discussion Groups
Original Rockhounds Discussion Group
Rockhounds Discussion Group on Yahoo Groups
Mineral Discussion Forum from Fabre Minerals - also available in Español

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

Vermiculite

(Mg,Fe++,Al)3(Al,Si)4O10(OH)2·4(H2O)
Dana No: 71.2.2d.3 Strunz No: VIII/H.21-10
Locality:

Notes: