Composition | SiO2 | Al2O3 | BeO | Fe2O3 | CaO | MgO | Na2O | K2O | MnO |
by wt. % | 65.40 | 19.08 | 12.30 | 0.80 | 1.34 | 0.48 | 0.55 | 0.004 | 0.05 |