Name
Formula
Dens. (Log)
(g/cm3)
tc
(µsec/ft)
ts
(µsec/ft)
Pe
U
GR
(API units)
Neutron Capture Cross Section
(c.u.)
SILICATES
Quartz SiO2
2.64
56
88
1.8
4.8
  
4.3
Opal (3.5% H2O) SiO2 (H2O).1209
2.13
58
 
1.8
3.7
  
5.0
Garnet* Fe3Al2(SiO4)3
4.31
 
  
11
48
  
45
Hornblende* Ca2NaMg2Fe2
AlSi8O22(O,OH)2
3.20
43.8
81.5
6.0
19
  
18
CARBONATES
Calcite CaCO3
2.71
49
88.4
5.1
13.8
  
7.1
Dolomite CaCO3MgCO3
2.85
44
72
3.1
9
  
4.7
Siderite FeCO3
3.89
47
 
15
57
  
52
OXIDATES
Hematite Fe2O3
5.18
42.9
79.3
21
111
  
101
Magnetite Fe3O4
5.08
73
 
22
113
  
103
FELDSPARS -- ALKALI*
Orthoclase KAlS3O8
2.52
69
  
2.9
7.2
~220
16
Anorthoclase KAlS3O8
2.59
    
2.9
7.4
~220
16
Microline KAlS3O8
2.53
    
2.9
7.2
~220
16
FELDSPARS -- PLAGIOCLASE*
Albite NaAlSi3O8
2.59
49
85
1.7
4.4
  
7.5
Anorthite CaAl2Si2O8
2.74
45
  
3.1
8.6
  
7.2
MICAS*
Muscovite KAl2(Si3AlO10)(OH)2
2.82
49
149
2.4
6.7
~270
17
Glauconite K0.7(Mg,Fe2,Al)
(Si4Al10)O2(OH)
2.86
    
4.8
14
  
21
Biotite K(Mg,Fe)3(AlSi3O10)(OH)2
~2.99
50.8
224
6.3
19
~275
30
CLAYS*
Kaolinite Al4Si4O10(OH)8
2.41
    
1.8
4.4
80-130
14
Chlorite (Mg,Fe,Al)6(Si,Al)4
O10(OH)8
2.76
    
6.3
17
180-250
25
Illite K1-1.5Al4(Si7-6.5,Al1-1.5)
O20(OH)4
2.52
    
3.5
8.7
250-300
18
Montmorillonite (Ca,Na)7(Al,Mg,Fe)4
(Si,Al)8O20(OH)4(H2O)n
2.12
    
2.0
4.0
150-200
14
EVAPORITES
Halite NaCl
2.04
67
120
4.7
9.5
  
754
Anhydrite CaSO4
2.98
50
  
5.1
15
  
12
Gypsum CaSO4(H2O)2
2.35
52
  
4.0
9.4
  
19
SULFIDES
Pyrite FeS2
4.99
39.2
62.1
17
85
  
90
* Mean value, which may vary for individual samples