|
Prismatic cristobalite
|
Platy cristobalite
|
Devitrification quartz
|
Quartz phenocryst
|
---|
MVO617
|
MontR1
|
MVO1406
|
MVO819
|
MVO819
|
MVO1236
|
MontR1
|
MontR1
|
MVO945
|
MVO287
|
---|
Na2O
|
1.14
|
0.30
|
0.41
|
0.98
|
0.70
|
0.96
|
0.14
|
n.d.
|
n.d.
|
n.d.
|
Al2O3
|
1.94
|
1.42
|
0.96
|
2.74
|
1.50
|
1.71
|
0.62
|
0.09
|
0.25
|
n.d.
|
SiO2
|
96.16
|
97.42
|
98.32
|
94.73
|
96.10
|
96.65
|
99.27
|
99.49
|
100.08
|
100.10
|
MgO
|
n.d.
|
0.02
|
n.d.
|
0.04
|
0.12
|
n.d.
|
0.02
|
n.d.
|
n.d.
|
n.d.
|
K2O
|
0.01
|
0.03
|
0.23
|
0.60
|
0.26
|
n.d.
|
0.03
|
0.13
|
n.d.
|
0.01
|
CaO
|
0.08
|
0.29
|
0.02
|
0.12
|
0.08
|
0.06
|
0.47
|
0.22
|
0.05
|
n.d.
|
TiO2
|
0.23
|
0.09
|
0.17
|
0.17
|
0.17
|
0.15
|
0.11
|
0.08
|
0.08
|
0.03
|
MnO
|
n.d.
|
n.d.
|
n.d.
|
n.d.
|
n.d.
|
n.d.
|
n.d.
|
n.d.
|
n.d.
|
n.d.
|
FeO
|
0.20
|
0.20
|
0.09
|
0.34
|
0.37
|
0.19
|
0.16
|
0.29
|
0.15
|
n.d.
|
Total
|
99.79
|
99.77
|
100.19
|
99.75
|
99.27
|
99.75
|
100.81
|
100.12
|
100.64
|
100.21
|
- Data are in oxide wt. %. n.d. = not detected.