Chemistry of Glass
The variation of chemical material used in the formation of glass can make drastic differences in the end product.
- Formers make up the largest percentage of glass mixtures. In typical soda lime silica glass the former is silica in the form of sand.
- Flux lowers the temperature at which the former will melt. Soda and potash both alkalis are common fluxes. Potash glass is slightly denser than soda.
- Stabilizers make the glass strong and water resistant. Calcium carbonate, calcined limestone is a stabilizer. Without a stabilizer, water and humidity attack and dissolve glass-lacking lime is often called "waterglass".
Materials Often Found in Glass Mixtures
- Silica: Sand, quarts and pebbles.
- Soda: Soda ash, natron, marine plant ashes
- Lime: Chalk, limestone
- Potash: Ashes of inland plants
- Lead: Oxidized lead metal
- Boron: Modern minerals
- Magnesium: Naturally occurring element
- Aluminum:Naturally occurring metal element
- Iron: Naturally occurring metal element
Chemistry of Colored Glass
The addition of various materials will change the color of the glass. The following are some of the materials and the colors they produce when added to the glass mixtures.
- Antimony Oxides: White colored glass
- Carbon Oxides: Amber (Brown) glass
- Chromium or Sulfur: Yellow colored glass
- Cobalt Aluminates: Turquoise colored glass
- Cobalt Oxide: Deep blue glass referred to as cobalt glass
- Cobalt Oxide: Purple or red glass when added to borosilicate glass mixture
- Cobalt Silicate: Violet-blue glass
- Copper or Gold: Red colored glass
- Iron Oxides: Green and brown colored glass
- Manganese and Cobalt Mix: Black colored glass
- Manganese Oxides: Amber (brown) as well as amethyst colored glass
- Selenium Oxide: Red colored glass
- Sulfur Oxides: Amber (brown) colored glass
- Tin Compounds: White colored glass