The composition of colourless glass: a review

A total of 1496 investigated colourless glass analyses have been collected with the aim of achieving a clear geographical, typological, chronological and compositional overview on this particular type of glass. Based on manganese and antimony contents, four main groups were characterised: naturally colourless, Mn-decoloured, Sb-decoloured and Mn/Sb-decoloured. Main achievements relates to the chronological distribution of manganese and antimony technologies, the former being associated to a long lasting technology which culminated during the Late Antique period while the latter being practically absent after the 8th century AD, being at its acme during the Roman imperial period. Except for naturally colourless glass, glass-making technology mostly implied the use of impure sands and natron, relegating the other components to a virtually irrelevant presence, except during the Late Antique and Medieval periods.