Environmental Engineering Reference
In-Depth Information
TABLE 5.28
Classification of Clay Minerals
a
Layers
Expansion
Group
Species
Crystallo chemial
Formula
Structure
(Schematic)
Two-sheet
Non-swelling
Kaolinite
Kaolinite
Al
4
(OH)
8
[Si
4
O
10
]
Si
Al, Mg, Fe
exchangeable
cations
K
O
OH
(1:1)
Dickite
Nacrite
10,0A
7,1 A
Non-swelling and swelling
Halloysite
Halloysite
Al
4
(OH)
8
[Si
4
O
10
](H
2
O)
4
Metahalloysite
Al
4
(OH)
8
[Si
4
O
10
](H
2
O)
2
H
2
O
KAOLINITE
HALLOYSITE
Swelling
Montmorillonite
Montmorillonite
{(Al
2
x
Mg
X
)(OH)
2
[Si
4
O
10
]
−X
NO
X
OH
2
0
(Smectite)
Beidellite
{(Al
2
(OH)
2
[(Al
2
Si)
4
O
10
]
−
X
NO
X
OH
2
0
−
X
NO
X
OH
2
0
Nontronite
{(Fe
2
X
Mg)(OH)
2
[Si
4
O
10
]}
10,0A
14,2 A
14,2 A
Three-sheet
Non-swelling
Illite
Illite-Varieties
(K
1
H
3
O)Al
2
(H
2
O
1
OH)
2
[AlSi
3
O
10
]
(Hydormica)
(2:1)
Swelling
Vermiculite
Vermiculite
(Mg
1
Fe)
3
(OH)
2
[(AlSi
3
O
10
] Mg (H
2
O)
4
Three-sheet
Non-swelling
14A-Chlorite
Chlorite-Varieties
(Al
1
Mg
1
Fe)
3
(OH)
2
[(Al
1
Si)
4
O
10
] Mg
3
(OH)
6
ILLITE MONTMORILLONITE
VERMICULITE
one-sheet (2:2)
(Normal Chlorite
14 A
CHLORITE
a
From Morin, W.J. and Tudor, P.C., U.S. Agency for International Development, Washington, DC, 1976.
