See Report on analysis by British Museum 1996 in Object info file and updated version of May 1999. These show that the chemical composition of the bowl is confirm those found for Roman glass and in some ways distinctly different from 19th-century glass from Venice. Cf. Sidney M. Goldstein, Pre-Roman...,Corning 1979, nr. 555 (afb. Pl. 30) = fragment of this type. David Grosse thought this to be not Roman but a 19th-century fake or copy.
There is, however, no proof of a 19th-century origin, and the bowl shows some distinct differences in relation to known 19th-century pieces. The canes ued are unrecorded for this period. Its provenance in 1868 puts it earlier than any of the documentary evidence of Muranese mosaic glass as well as any known 19th-century pieces.
David Grose examined the piece on 26-4-1999 and still thought that this piece is not Roman, for various reasons:
1 The cane sections are too large
2 Roman multi coloured 'flag' canes always consist of three layers, ours don't
3 The outside of the piece seems to be covered entirely with colourless glass. This is not the case with Roman examples.
4 The rim is too thin.
5 The ribs are too thin
6 The green is not of the right colour
7 The foot is added to the bowl, is not typical
8 There is no evidence of any corrosion
9 The foot is slightly too large for the bowl
The scientific evidence is not 100% conclusive!