| Constituent |
Sample I % |
Sample II % |
| Total SiO2 |
72.37 |
73.50 |
| Al2O3 |
11.97 |
12.50 |
| Fe2O3 |
0.53 |
0.22 |
| Na2O |
2.28 |
2.13 |
| K2O |
8.38 |
9.30 |
| MgO |
0.25 |
0.23 |