It varies in colour from greyish to bright yellow or greenish-brown, the first-named being the purest.
A greenish alloy used by goldsmiths contains 70% of silver and 30% of gold.
All the other examples have the lower portion covered in like manner by a network of circles standing nearly a quarter of an inch from the body of the cup. An example connected with the specimens just described is the cup belonging to Baron Lionel de Rothschild; though externally of an opaque greenish colour, it is by transmitted light of a deep red.
The glass in all is greenish, very thick, with many bubbles, and has been cut with the wheel; in some instances circles and cones, and in one the outlines of the figure of a leopard, have been left standing up, the rest of the surface having been laboriously cut away.
Greenish colour, so that they offer no attractions to insect visitors and their form is correspondingly regular.