Chemistry Reference
In-Depth Information
Table 3.18
Representative hyperfine parameters at RT of some phyllosilicates
Mineral
Site
d
Fe
(mm/s)
D (mm/s)
Mineral
Site
d
Fe
(mm/s)
D (mm/s)
1:1 dioctahedral
Kaolinite
Fe
3+
0.48
0.52
Fe
2+
1.1-1.3
2.4-2.9
1:1 trioctahedral
Antigorite
Fe
2+
1.14
2.68-2.76
Fe
3+
0.37-0.42
0.65-0.85
Fe
2+
Greenalite
1.15
2.75
Fe
2+
Berthierine
1.15
2.62
2:1 dioctahedral
Muscovite
Fe
3+
(M2)
0.40
0.72
Fe
2+
(M2)
1.13
3.00
Fe
2+
(M1)
1.12
2.20
Fe
3+
(M2)
Illite
0.33
0.59-0.73
Fe
3+
(M1)
0.38
1.21
Fe
2+
(M2)
1.14
2.75
Fe
3+
(M2)
Nontronite
0.36-0.39
0.24-0.27
Fe
3+
(M1)
0.37-0.40
0.59-0.68
Fe
3+
(M2)
Glauconite
0.34
0.33
Fe
3+
(M1)
0.32
0.69
Fe
2+
(M2)
1.1
2.68
Fe
2+
(M1)
1.1
1.7-1.9
Fe
3+
(interlayer)
0.50
0.5-0.8
Fe
3+
(M2)
Celadonite
0.35
0.39
Fe
2+
(M2)
1.12
2.64
Fe
2+
(M1)
1.12
1.76
Fe
3+
(DSS)
0.39
1.16
2:1 trioctahedral
Talc
Fe
2+
(M2)
1.13
2.6
Fe
2+
(M2)
Biotite
1.12-1.14
2.57-2.63
Fe
2+
(M1)
1.07-1.15
2.12-2.22
Fe
3+
(M2)
0.39-0.44
0.37-0.66
Fe
3+
(M1)
0.39-0.49
1.16-1.24
Fe
3+
(M2)
Vermiculite
0.29
0.57
Fe
3+
(M1)
0.37
1.10
Fe
2+
(M2)
1.11
2.58
Fe
2+
(M2)
Chlorite
1.12
2.68
Fe
2+
(M1)
1.12
2.3-2.4
Fe
2+
(brucite)
1.16-1.20
2.67-2.70
Fe
3+
(?)
0.38-0.46
0.5-0.75
a much more significant replacement of Si by Al or Fe
3+
in the tetrahedra than in
celadonite, for which the substitution is considered to be 20 at % or less. The
Mössbauer spectra of glauconites can be consistently fitted with two ferrous
doublets (cis and trans), two ferric doublets (cis and trans) and a third ferric
