Many Roman glass vessels appear to shimmer with color like a peacock's tail; others, at first glance, look as if they are covered with patches of gold foil. Neither of these effects were deliberately produced by a Roman glassworker. Instead they result from a gradual weathering that glass undergoes when it is buried for a long period in damp soil.

Unguentarium with chalky soil encrustation
1st century A.D.
Ht., 18.5 cm



1) Brill, R.H., 1963: "Ancient Glass," Scientific American 209:5, 120-131.

2) Fleming, S.J., 1999: Roman Glass: Reflections on Cultural Change, Appendix A (University of Pennsylvania Museum, Philadelphia).

3) Kaplan, M.F. and Mendel, J.E., 1982: "Ancient Glass and the Safe Disposal of Nuclear Waste," Archaeology 35:4, 22-29.

4) Isard, J.O., 1986: "Influence of Alkaline Earth Ions on the Corrosion of Glasses," Physics and Chemistry of Glasses 27:2, 55-58.

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