This is an exceptional vessel pure in form and of rare emerald green colour, achieved through the addition of copper to the molten glass. For the colour, see Jackson, 2012, pp. 109-117.
This type of mould-blown bowl, which was derived from the earlier cast vessels, are found throughout the Mediterranean with sporadic finds around the Black Sea and in the northwestern provinces, cf. Price, 1991, p. 72 (and pl. XVI,d for an example found at Usk, Gwent, South Wales); Whitehouse, 2001, pp. 30-1, no. 498 and Stern, 1995, p. 113, no. 14.