Chemical Composition
The following is a typical analysis of borosilicate glass 3.3 (Element % by weight)
| Silica SiO2 | 80,60% | Magnesium oxide MgO | 0,05% |
| Boric oxide B2O3 | 12,60% | Iron oxide Fe2O3 | 0,04% |
| Sodium oxide Na2O | 4,20% | Calcium oxide CaO | 0,10% |
| Alumina Al2O3 | 2,20% | Chlorine Cl | 0,10% |
There may be heavy metals in a concentration of less than 5 ppm.
