Soda glass
Description
Common name for glass having a high sodium content. Soda glass has the approximate composition 71-78% SiO2, 12-17% Na2O, 5-15% CaO, and 1-4% other. The soda is added as soda ash (carbonate sodium carbonate), niter (nitrate sodium nitrate) and/or salt cake (sulfate sodium sulfate). The calcium is added as limestone (carbonate calcium carbonate) or burnt lime (oxide calcium oxide) and the silica is added as sand (dioxide silicone dioxide). Cullet or broken glass, is used as a flux. Soda glass was also called common glass. Common glass often has a green tinge due to iron impurities in the ingredients.
Synonyms and Related Terms
common glass; soda lime glass; soda-lime glass; soda-lime-silica glass; verre sodique (Fr.); vidro sdico (Port.); standard window glass; Corning 0081; alkali glass
| Melting Point | 695 (softens) |
|---|---|
| Density | 2.47 |
| Refractive Index | 1.512 |
Authority
- G.S.Brady, G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 361
- Susan E. Schur, Susan E. Schur, Conservation Terminology: A review of Past & Current Nomenclature of Materials, Technology and Conservation, Spring (p.34-39); Summer (p.35-38); Fall (p.25-36), 1985
- Dictionary of Building Preservation, Ward Bucher, ed., John Wiley & Sons, Inc., New York City, 1996
- Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976