Colour in glass may be obtained by addition of homogenously distributed electrically charged ions (or colour centres). While ordinary soda–lime glass appears colourless in thin section, iron(II) oxide (FeO) impurities produce a green tint in thick sections. Manganese dioxide (MnO2), which gives glass a purple colour, may be added to remove the green tint given by FeO. FeO and chromium(III) oxide (Cr2O3) additives are used in the production of green bottles. Iron (III) oxide, on the other-hand, produces yellow or yellow-brown glass. Low concentrations (0.025 to 0.1%) of cobalt oxide (CoO) produce rich, deep blue cobalt glass. Chromium is a very powerful colouring agent, yielding dark green.Chemical Fact Sheet – Chromium www.speclab.com. Sulphur combined with carbon and iron salts produces amber glass ranging from yellowish to almost black.David M Issitt. Substances Used in the Making of Coloured Glass 1st.glassman.com. A glass melt can also acquire an amber colour from a reducing combustion atmosphere. Cadmium sulfide produces imperial red, and combined with selenium can produce shades of yellow, orange, and red. Addition of copper(II) oxide (CuO) produces a turquoise colour in glass, in contrast to copper(I) oxide (Cu2O) which gives a dull red-brown colour.
colour in glass may be obtained by addition of homogenously distributed electrically charged ions (or colour centres) while ordinary soda–lime glass appears colourless in thin section iron(ii) oxide (feo) impurities produce a green tint in thick sections manganese dioxide (mno2) which gives glass a purple colour may be added to remove the green tint given by feo feo and chromium(iii) oxide (cr2o3) additives are used in the production of green bottles iron (iii) oxide on the other-hand produces yellow or yellow-brown glass low concentrations (0025 to 01%) of cobalt oxide (coo) produce rich deep blue cobalt glass chromium is a very powerful colouring agent yielding dark greenchemical fact sheet – chromium wwwspeclabcom sulphur combined with carbon and iron salts produces amber glass ranging from yellowish to almost blackdavid m issitt substances used in the making of coloured glass 1stglassmancom a glass melt can also acquire an amber colour from a reducing combustion atmosphere cadmium sulfide produces imperial red and combined with selenium can produce shades of yellow orange and red addition of copper(ii) oxide (cuo) produces a turquoise colour in glass in contrast to copper(i) oxide (cu2o) which gives a dull red-brown colour