A reduced glass contains sulphur in the reduced state as a sulphide or polysulphide. Reduction is usually via carbon and is used in combination with iron to produce amber glass used mostly for liquids affected by the sun. Oxidized glass contains sulphur in the oxidized state as sulphate and indeed sulphates like gypsum or sodium sulphate are added as oxidants and result in flint (clear) glass but this can be coloured with chrome salts for green glass, selenium for reddish glass and cobalt for blueish glass. Hope this helps.
Sankaranarayanan Hariharan
Nice and Simple Explanation !!! :)
Dewald Kloppers
A reduced glass contains sulphur in the reduced state as a sulphide or polysulphide. Reduction is usually via carbon and is used in combination with iron to produce amber glass used mostly for liquids affected by the sun. Oxidized glass contains sulphur in the oxidized state as sulphate and indeed sulphates like gypsum or sodium sulphate are added as oxidants and result in flint (clear) glass but this can be coloured with chrome salts for green glass, selenium for reddish glass and cobalt for blueish glass. Hope this helps.