| 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 |