| Type of glass | Silica, SiO2 | Soda, Na2O | Lime, CaO | Potash, K2O | Magnesia, MgO | Alumina, Al2O3 | Iron Oxide, Fe2O3 | Boric Oxide, B2O3 | Lead Oxide, PbO |
| Modern soda glass | 74 | 16 | 5 | <1 | 4 | 1 | - | - | - |
| Baking/Laboratory glass | 80 | 4 | 0.4 | - | 2 | - | 13 | - | |
| Lead crystal | 35 | - | - | 7 | - | - | - | - | 58 |
| 96% silica (high T) | 96.5 | - | - | - | - | 0.5 | - | 3 | - |
| Roman soda glass | 67 | 18 | 8 | 1 | 1 | 2.5 | 0.5 | 0 | trace |
| Type of Glass |
Annealing point, °C |
Softening point, °C | Working point, °C |
|---|---|---|---|
| Soda lime glass | 520 | 700 | 1010 |
| Borosilicate glass (Pyrex, Kimax, etc.) | 550 | 820 | 1245 |
| 96% silica | 910 | 1500 | |
| Fused silica (quartz glass) | 1120 | 1710 |
Department of Chemistry
Houston, TX
6100 Main St., Houston, TX 77005-1827 | Mailing Address: P.O. Box 1892, Houston, TX 77251-1892 713-348-0000 |