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Vermiculite

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Formula:
(Mg,Fe,Al)
 
3
((Al,Si)
 
4
O
 
10
)(OH)
 
2
· 4H
 
2
O
System:MonoclinicColour:Brown, bronze-yellow
Hardness:1½ - 2
Name:From Latin "vermiculare", to breed worms, in allusion to its peculiar exfoliation on intense heating.


Montmorillonite-Vermiculite Group.

Forms as an alteration product of biotite or phlogopite, by weathering or hydrothermal action. Vermiculite is mined as a natural insulation material.

Classification of Vermiculite

IMA status:Valid - first described prior to 1959 (pre-IMA) - "Grandfathered"
Strunz 8th edition ID:8/H.21-10
Nickel-Strunz 10th (pending) edition ID:9.EC.50

9 : SILICATES (Germanates)
E : Phyllosilicates
C : Phyllosilicates with mica sheets, composed of tetrahedral and octahedral nets
Dana 8th edition ID:71.2.2d.3

71 : PHYLLOSILICATES Sheets of Six-Membered Rings
2 : Sheets of 6-membered rings with 2:1 layers
Hey's CIM Ref.:16.19.22

16 : Silicates Containing Aluminum and other Metals
19 : Aluminosilicates of Fe and Mg
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Type Occurrence of Vermiculite

Type Locality:Millbury, Worcester Co., Massachusetts, USA
Year of Discovery:1824

Physical Properties of Vermiculite

Colour:Brown, bronze-yellow
Hardness (Mohs):1½ - 2

Crystallography of Vermiculite

Crystal System:Monoclinic
Cell Parameters:a = 5.24Å, b = 9.17Å, c = 28.6Å
β = 94.6°
Ratio:a:b:c = 0.571 : 1 : 3.119
Unit Cell Volume:V 1,369.83 ų (Calculated from Unit Cell)
X-Ray Powder Diffraction:
Image Loading

Radiation - Copper Kα
Data Set:
Horizontal Axis: ° to ° Vertical Axis: % Source Data: Filtered Data:
Data courtesy of RRUFF project at University of Arizona, used with permission.

Optical Data of Vermiculite

Type:Biaxial (-)
RI values: nα = 1.525 - 1.561 nβ = 1.545 - 1.581 nγ = 1.545 - 1.581
Maximum Birefringence:δ = 0.020

Chart shows birefringence interference colour range (at 30µm thickness) and does not take into account mineral colouration.
Surface Relief:Low
Dispersion:weak

Chemical Properties of Vermiculite

Formula:
(Mg,Fe,Al)
 
3
((Al,Si)
 
4
O
 
10
)(OH)
 
2
· 4H
 
2
O
Simplified for copy/paste:(Mg,Fe,Al)3((Al,Si)4O10)(OH)2·4H2O
Essential elements:Al, H, Mg, O
All elements listed in formula:Al, Fe, H, Mg, O, Si
Common Impurities:Ca,Na,K

Relationship of Vermiculite to other Species

Structurally related to group(s):
Montmorillonite-Vermiculite Group
Related Minerals - Nickel-Strunz Grouping):

- +
9.EC.05Minnesotaite
(Fe,Mg)
 
3
(Si
 
4
O
 
10
)(OH)
 
2
9.EC.05Talc
Mg
 
3
(Si
 
4
O
 
10
)(OH)
 
2
9.EC.05Willemseite
(Ni,Mg)
 
3
(Si
 
4
O
 
10
)(OH)
 
2
9.EC.10Ferripyrophyllite
Fe
3+
2
(Si
 
4
O
 
10
)(OH)
 
2
9.EC.10Pyrophyllite
Al
 
2
(Si
 
4
O
 
10
)(OH)
 
2
9.EC.15Boromuscovite
KAl
 
2
(BSi
 
3
O
 
10
)(OH)
 
2
9.EC.15Celadonite
K(Mg,Fe
2+
 
)Fe
3+
 
(Si
 
4
O
 
10
)(OH)
 
2
9.EC.15Chernykhite
(Ba,Na)(V
3+
 
,Al,Mg)
 
2
((Si,Al)
 
4
O
 
10
)(OH)
 
2
9.EC.15Montdorite
(K,Na)
 
2
(Fe
2+
 
,Mn
2+
 
,Mg)
 
5
(Si
 
4
O
 
10
)
 
2
(OH,F)
 
4
9.EC.15Muscovite
KAl
 
2
(AlSi
 
3
O
 
10
)(OH)
 
2
9.EC.15Nanpingite
CsAl
 
2
(AlSi
 
3
O
 
10
)(OH,F)
 
2
9.EC.15Paragonite
NaAl
 
2
(AlSi
 
3
O
 
10
)(OH)
 
2
9.EC.15Roscoelite
K(V
3+
 
,Al)
 
2
(AlSi
 
3
O
 
10
)(OH)
 
2
9.EC.15Tobelite
(NH
 
4
,K)Al
 
2
(AlSi
 
3
O
 
10
)(OH)
 
2
9.EC.15Aluminoceladonite
K(Mg,Fe
2+
 
)Al(Si
 
4
O
 
10
)(OH)
 
2
9.EC.15Chromphyllite
K(Cr,Al)
 
2
(AlSi
 
3
O
 
10
)(OH,F)
 
2
9.EC.15Ferro-aluminoceladonite
K(Fe
2+
 
,Mg)(Al,Fe
3+
 
)(Si
 
4
O
 
10
)(OH)
 
2
9.EC.15Ferroceladonite
K(Fe
2+
 
,Mg)(Fe
3+
 
,Al)(Si
 
4
O
 
10
)(OH)
 
2
9.EC.15Chromceladonite
K(Mg,Fe
2+
 
)(Cr,Al)(Si
 
4
O
 
10
)(OH)
 
2
9.EC.15Tainiolite
KLiMg
 
2
(Si
 
4
O
 
10
)F
 
2
9.EC.15Ganterite
(Ba,Na,K)(Al,Mg)
 
2
(AlSi
 
3
O
 
10
)(OH)
 
2
9.EC.20Annite
KFe
2+
3
(AlSi
 
3
O
 
10
)(OH)
 
2
9.EC.20Ephesite
LiNaAl
 
2
(Al
 
2
Si
 
2
O
 
10
)(OH)
 
2
9.EC.20Hendricksite
K(Zn,Mg,Mn
2+
 
)
 
3
(AlSi
 
3
O
 
10
)(OH)
 
2
9.EC.20Masutomilite
(K,Rb)(Li,Mn
3+
 
,Al)
 
3
(AlSi
 
3
O
 
10
)(F,OH)
 
2
9.EC.20Norrishite
KLiMn
3+
2
(Si
 
4
O
 
10
)O
 
2
9.EC.20Phlogopite
KMg
 
3
(AlSi
 
3
O
 
10
)(OH,F)
 
2
9.EC.20Polylithionite
KLi
 
2
Al(Si
 
4
O
 
10
)(F,OH)
 
2
9.EC.20Preiswerkite
NaMg
 
2
Al(Al
 
2
Si
 
2
O
 
10
)(OH)
 
2
9.EC.20Siderophyllite
KFe
2+
2
Al(Al
 
2
Si
 
2
O
 
10
)(OH)
 
2
9.EC.20Tetraferriphlogopite
KMg
 
3
(Fe
3+
 
Si
 
3
O
 
10
)(OH,F)
 
2
9.EC.20Fluorotetraferriphlogopite
KMg
 
3
(Fe
3+
 
Si
 
3
O
 
10
)F
 
2
9.EC.20Wonesite
(Na,K)(Mg,Fe,Al)
 
6
((Al,Si)
 
4
O
 
10
)
 
2
(OH,F)
 
4
9.EC.20Eastonite
KMg
 
2
Al(Al
 
2
Si
 
2
O
 
10
)(OH)
 
2
9.EC.20Tetraferriannite
KFe
2+
3
((Fe
3+
 
,Al)Si
 
3
O
 
10
)(OH)
 
2
9.EC.20Trilithionite
K(Li,Al)
 
3
(AlSi
 
3
O
 
10
)(F,OH)
 
2
9.EC.20Fluorannite
KFe
2+
3
(AlSi
 
3
O
 
10
)(F,OH)
 
2
9.EC.20Shirokshinite
KNaMg
 
2
(Si
 
4
O
 
10
)F
 
2
9.EC.20Shirozulite
K(Mn
2+
 
,Mg)
 
3
(AlSi
 
3
O
 
10
)(OH)
 
2
9.EC.20Sokolovaite
CsLi
 
2
Al(Si
 
4
O
 
10
)F
 
2
9.EC.20Aspidolite
NaMg
 
3
(AlSi
 
3
O
 
10
)(OH)
 
2
9.EC.20Fluorophlogopite
KMg
 
3
(AlSi
 
3
O
 
10
)(F,OH)
 
2
9.EC.20UM2004-49-SiO:AlCsFHKLi
(Cs,K)(Al,Li)
 
2.6
((Si,Al)
 
4
O
 
10
)(F,OH)
 
2
9.EC.20Suhailite
(NH
 
4
)Fe
2+
3
(AlSi
 
3
O
 
10
)(OH)
 
2
9.EC.20Yangzhumingite
KMg
 
2.5
(Si
 
4
O
 
10
)F
 
2
9.EC.20Orlovite
KLi
 
2
Ti(Si
 
4
O
 
10
)OF
9.EC.20Oxyphlogopite
K(Mg,Ti,Fe)
 
3
[(Si,Al)
 
4
O
 
10
](O,F)
 
2
9.EC.25Brammallite
(Na,H
 
3
O)(Al,Mg,Fe)
 
2
((Si,Al)
 
4
O
 
10
)(OH)
 
2
9.EC.30Margarite
CaAl
 
2
(Al
 
2
Si
 
2
O
 
10
)(OH)
 
2
9.EC.35Anandite
(Ba,K)(Fe
2+
 
,Mg)
 
3
((Si,Al,Fe)
 
4
O
 
10
)(S,OH)
 
2
9.EC.35Bityite
LiCaAl
 
2
(AlBeSi
 
2
O
 
10
)(OH)
 
2
9.EC.35Clintonite
Ca(Mg,Al)
 
3
(Al
 
3
SiO
 
10
)(OH)
 
2
9.EC.35Kinoshitalite
(Ba,K)(Mg,Mn
2+
 
,Al)
 
3
(Al
 
2
Si
 
2
O
 
10
)(OH)
 
2
9.EC.35Ferrokinoshitalite
(Ba,K)(Fe
2+
 
,Mg)
 
3
(Al
 
2
Si
 
2
O
 
10
)(OH,F)
 
2
9.EC.35Oxykinoshitalite
(Ba,K)(Mg,Ti,Fe
3+
 
,Fe
2+
 
)
 
3
((Si,Al)
 
4
O
 
10
)(O,OH,F)
 
2
9.EC.35Fluorokinoshitalite
BaMg
 
3
(Al
 
2
Si
 
2
O
 
10
)F
 
2
9.EC.40Beidellite
(Na,Ca
 
0.5
)
 
0.3
Al
 
2
((Si,Al)
 
4
O
 
10
)(OH)
 
2
· nH
 
2
O
9.EC.40Kurumsakite
(Zn,Ni,Cu)
 
8
Al
 
8
V
5+
2
Si
 
5
O
 
35
· 27H
 
2
O (?)
9.EC.40Montmorillonite
(Na,Ca)
 
0.33
(Al,Mg)
 
2
(Si
 
4
O
 
10
)(OH)
 
2
· nH
 
2
O
9.EC.40Nontronite
Na
 
0.3
Fe
 
2
((Si,Al)
 
4
O
 
10
)(OH)
 
2
· nH
 
2
O
9.EC.40Volkonskoite
Ca
 
0.3
(Cr,Mg,Fe)
 
2
((Si,Al)
 
4
O
 
10
)(OH)
 
2
· 4H
 
2
O
9.EC.40Yakhontovite
(Ca,Na)
 
0.5
(Cu,Fe,Mg)
 
2
(Si
 
4
O
 
10
)(OH)
 
2
· 3H
 
2
O
9.EC.45Hectorite
Na
 
0.3
(Mg,Li)
 
3
(Si
 
4
O
 
10
)(F,OH)
 
2
9.EC.45Saponite
Ca
 
0.25
(Mg,Fe)
 
3
((Si,Al)
 
4
O
 
10
)(OH)
 
2
· nH
 
2
O
9.EC.45Sauconite
Na
 
0.3
Zn
 
3
((Si,Al)
 
4
O
 
10
)(OH)
 
2
· 4H
 
2
O
9.EC.45Spadaite
MgSiO
 
2
(OH)
 
2
· H
 
2
O (?)
9.EC.45Stevensite
(Ca,Na)
 
x
Mg
 
3-x
(Si
 
4
O
 
10
)(OH)
 
2
9.EC.45Swinefordite
Li(Al,Li,Mg)
 
4
((Si,Al)
 
4
O
 
10
)
 
2
(OH,F)
 
4
· nH
 
2
O
9.EC.45Zincsilite
Zn
 
3
(Si
 
4
O
 
10
)(OH)
 
2
· 4H
 
2
O
9.EC.45Ferrosaponite
Ca
 
0.3
(Fe
2+
 
,Mg,Fe
3+
 
)
 
3
((Si,Al)
 
4
O
 
10
)(OH)
 
2
· 4H
 
2
O
9.EC.55Baileychlore
(Zn,Fe,Al,Mg)
 
6
((Si,Al)
 
4
O
 
10
)(OH)
 
8
9.EC.55Chamosite
(Fe
2+
 
,Mg)
 
5
Al(AlSi
 
3
O
 
10
)(OH)
 
8
9.EC.55Clinochlore
(Mg,Fe
2+
 
)
 
5
Al(AlSi
 
3
O
 
10
)(OH)
 
8
9.EC.55Cookeite
(Al
 
2
Li)Al
 
2
(AlSi
 
3
O
 
10
)(OH)
 
8
9.EC.55Franklinfurnaceite
Ca
 
2
Fe
3+
 
Mn
2+
3
Mn
3+
 
(Zn
 
2
Si
 
2
O
 
10
)(OH)
 
8
9.EC.55Gonyerite
(Mn
2+
 
,Mg)
 
5
Fe
3+
 
(Fe
3+
 
Si
 
3
O
 
10
)(OH)
 
8
9.EC.55Nimite
(Ni,Mg,Al)
 
6
((Si,Al)
 
4
O
 
10
)(OH)
 
8
9.EC.55Orthochamosite
(Fe
2+
 
,Mg,Fe
3+
 
)
 
5
Al(AlSi
 
3
O
 
10
)(OH,O)
 
8
9.EC.55Pennantite
Mn
2+
5
Al(AlSi
 
3
O
 
10
)(OH)
 
8
9.EC.55Sudoite
(Mg,Fe
2+
 
)
 
2
Al
 
3
(AlSi
 
3
O
 
10
)(OH)
 
8
9.EC.55Donbassite
Al
 
4.33
(AlSi
 
3
O
 
10
)(OH)
 
8
9.EC.55Glagolevite
Na(Mg,Al)
 
6
(AlSi
 
3
O
 
10
)(OH,O)
 
8
9.EC.55Borocookeite
Li
 
1+3x
Al
 
4-x
(BSi
 
3
O
 
10
)(OH)
 
8
9.EC.60Aliettite
Ca
 
0.2
Mg
 
6
((Si,Al)
 
8
O
 
20
)(OH)
 
4
· 4H
 
2
O
9.EC.60Corrensite
(Mg,Fe)
 
9
((Si,Al)
 
8
O
 
20
)(OH)
 
10
· nH
 
2
O
9.EC.60Dozyite
Mg
 
7
Al
 
2
(Al
 
2
Si
 
4
O
 
15
)(OH)
 
12
9.EC.60Hydrobiotite
K(Mg,Fe
2+
 
)
 
6
((Si,Al)
 
8
O
 
20
)(OH)
 
4
· nH
 
2
O
9.EC.60Karpinskite
(Ni,Mg)
 
2
Si
 
2
O
 
5
(OH)
 
2
(?)
9.EC.60Kulkeite
Mg
 
8
Al(AlSi
 
7
O
 
20
)(OH)
 
10
9.EC.60Lunijianlaite
Li
 
0.7
Al
 
6.2
(AlSi
 
7
O
 
20
)(OH,O)
 
10
9.EC.60Rectorite
(Na,Ca)Al
 
4
((Si,Al)
 
8
O
 
20
)(OH)
 
4
· 2H
 
2
O
9.EC.60Saliotite
(Li,Na)Al
 
3
(AlSi
 
3
O
 
10
)(OH)
 
5
9.EC.60Tosudite
Na
 
0.5
(Al,Mg)
 
6
((Si,Al)
 
8
O
 
18
)(OH)
 
12
· 5H
 
2
O
9.EC.60Brinrobertsite
Na
 
0.3
Al
 
4
(Si
 
4
O
 
10
)
 
2
(OH)
 
4
· 3.5 H
 
2
O
9.EC.65Macaulayite
(Fe,Al)
 
24
Si
 
4
O
 
43
(OH)
 
2
9.EC.70Burckhardtite
Pb
 
2
(Fe
3+
 
,Mn
3+
 
)Te
4+
 
(AlSi
 
3
O
 
10
)O
 
2
(OH)
 
2
· H
 
2
O
9.EC.75Ferrisurite
(Pb,Ca)
 
2.4
Fe
3+
2
(Si
 
4
O
 
10
)(CO
 
3
)
 
1.7
(OH)
 
3
· nH
 
2
O
9.EC.75Surite
(Pb,Ca)
 
3
(Al,Fe
2+
 
,Mg)
 
2
((Si,Al)
 
4
O
 
10
)(CO
 
3
)
 
2
(OH)
 
2
9.EC.75Niksergievite
(Ba,Ca)
 
2
Al
 
3
(AlSi
 
3
O
 
10
)(CO
 
3
)(OH)
 
6
· nH
 
2
O
9.EC.80Kegelite
Pb
 
8
Al
 
4
(Si
 
8
O
 
20
)(SO
 
4
)
 
2
(CO
 
3
)
 
4
(OH)
 
8
Related Minerals - Hey's Index Grouping:

- +
16.19.1Indialite
Mg
 
2
Al
 
3
(AlSi
 
5
O
 
18
)
16.19.2Cordierite
(Mg,Fe)
 
2
Al
 
3
(AlSi
 
5
O
 
18
)
16.19.3Sekaninaite
(Fe,Mg)
 
2
Al
 
3
(AlSi
 
5
O
 
18
)
16.19.4Ferro-gedrite
☐{Fe
2+
2
}{Fe
2+
3
Al
 
2
}(Al
 
2
Si
 
6
O
 
22
)(OH)
 
2
16.19.5Staurolite
(Fe
2+
 
,Mg,Zn)
 
1.5-2
Al
 
9
(SiO
 
4
)
 
4
O
 
6
(OH,O)
 
2
16.19.6Chloritoid
(Fe
2+
 
,Mg,Mn
2+
 
)Al
 
2
(SiO
 
4
)O(OH)
 
2
16.19.7Amesite
Mg
 
2
Al(AlSiO
 
5
)(OH)
 
4
16.19.8Corundophilite
(Mg,Fe,Al)
 
6
(Si,Al)
 
4
O
 
10
(OH)
 
8
16.19.9Yoderite
Mg(Al,Fe
3+
 
)
 
3
(SiO
 
4
)
 
2
O(OH)
16.19.10Delessite
(Mg,Fe,Fe,Al)(Si,Al)
 
4
O
 
10
(O,OH)
 
8
16.19.11Ferrocarpholite
(Fe
2+
 
,Mg)Al
 
2
(Si
 
2
O
 
6
)(OH)
 
4
16.19.12Magnesiocarpholite
(Mg,Fe
2+
 
)Al
 
2
(Si
 
2
O
 
6
)(OH)
 
4
16.19.13Chamosite
(Fe
2+
 
,Mg)
 
5
Al(AlSi
 
3
O
 
10
)(OH)
 
8
16.19.14Orthochamosite
(Fe
2+
 
,Mg,Fe
3+
 
)
 
5
Al(AlSi
 
3
O
 
10
)(OH,O)
 
8
16.19.15Berthierine
(Fe
2+
 
,Fe
3+
 
,AlMg)
 
2-3
((Si,Al)
 
2
O
 
5
)(OH)
 
4
16.19.16Odinite
(Fe,Mg,Al,Fe,Ti,Mn)
 
2.4
((Si,Al)
 
2
O
 
5
)(OH)
 
4
16.19.17Clinochlore
(Mg,Fe
2+
 
)
 
5
Al(AlSi
 
3
O
 
10
)(OH)
 
8
16.19.18Gedrite
☐{Mg
 
2
}{Mg
 
3
Al
 
2
}(Al
 
2
Si
 
6
O
 
22
)(OH)
 
2
16.19.19Magnesiogedrite
16.19.20Diabantite
(Mg,Fe,Al)
 
6
((Si,Al)
 
4
O
 
10
)(OH)
 
8
16.19.21Sudoite
(Mg,Fe
2+
 
)
 
2
Al
 
3
(AlSi
 
3
O
 
10
)(OH)
 
8
16.19.23Corrensite
(Mg,Fe)
 
9
((Si,Al)
 
8
O
 
20
)(OH)
 
10
· nH
 
2
O

Other Names for Vermiculite

Synonyms:
BrodrickiteCulsageeiteJefferisiteZonolite
Other Languages:
German:Vermiculit
Russian:Вермикулит
Simplified Chinese:蛭石
Spanish:Vermiculita
Varieties:
BataviteCopper VermiculiteEastonite (of Hamilton)Lucasite (of Chatard)Vaalite

Other Information

Health Warning:No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

References for Vermiculite

Reference List:

- +
American Journal of Science (1824): 7: 55.

American Mineralogist (1966): 51: 1124.

American Mineralogist (1975): 60: 175.

Clays and Clay Minerals (1992): 40: 335.

Badreddine, R.; Vandormael, D.; Fransolet, A.-M.; Long, G. J.; Stone, W. E. E. & Grandjean, F. (2002): A comparative X-ray diffraction, Mossbauer and NMR spectroscopic study of the vermiculites from Beni Bousera, Morocco and Palabora, Republic of South Africa. Clay Minerals 37, 367-376.

Internet Links for Vermiculite

Search Engines:
  • Look for Vermiculite on Google
  • Look for Vermiculite images on Google
  • External Links:
  • Look for Vermiculite on Webmineral
  • Look for Vermiculite on Athena Mineralogy
  • Look for Vermiculite on Wikipedia
  • Look for Vermiculite on Mineralien Atlas
  • Raman and XRD data at RRUFF project
  • American Mineralogist Crystal Structure Database
  • Vermiculite details from Handbook of Mineralogy (PDF)
  • Mineral Dealers:
  • Mineral Classics - Worldwide Collector Quality Minerals and Gems
  • High-end worldwide specimens & outstanding customer service
  • Find Vermiculite on www.crystalclassics.co.uk
  • Buy from McDougall Minerals
  • Buy RARE Minerals from Rocks of Africa
  • Rare and Unusual minerals at Mineralogical Research Company
  • Fine minerals from bisbeeborn.com
  • The Arkenstone - Fine Minerals
  • Lapis Mineral Magazin
  • Buy rare minerals from Excalibur Minerals
  • Fabre Minerals - search for Vermiculite specimens
  • Buy from David K Joyce minerals
  • Localities for Vermiculite

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