The technique of making gold-glass became widespread in the western part of the empire in the second half of the 3rd century. It continued until the time of Justinian, although it was at its height in the 4th century. A design was made in gold-leaf on a thin layer of glass, usually with additional colours too, and another layer of glass was then sealed over the top. Most gold-glasses were flat circles and could be used as the bases of drinking vessels, or as medallions. They could also be embedded in the plaster of catacomb graves; one Jewish one has been found in situ (no.88), and the marks left by many in the plaster have been noted. The original use of most is in fact unclear, and their findspots are seldom recorded. Schmidt (1980), p.274, suggests that they might be given by Jews at festivals.

Schüler (1966) counted about 450 known gold-glasses, including 14 identified as Jewish. It is usually assumed that gold-glasses are Christian unless they are demonstrably not, but many have no specifically Christian content. There are several with Jewish symbols but no text. The most important of these are:

i. Garrucci (1864), p.43, tav.V.5; (1880), tav.490.5 (facsimile); Goodenough (1953), iii pl.976; Morey (1959), p.34 no.173, pl.XXI (photograph); Barag (1970), fig.3 (photograph); (1971), col.608, pl.12 (colour photograph); Schmidt (1980), pp.273-4 no.13.

Shofar between two lulabs with roots (?).

Biblioteca Vaticana. Small green glass medallion, 2.5 cm. diameter.