The History And Technology Of Renaissance Venetian Chalcedony Glass

Chalcedony glass is distinguished by its variegated and veined appearance with colours such as green, plue, purple and yellow, often intermingling on the surface of the glass with a swirled effect. When chalcedony is viewed so that it is illuminated by transmitted light, it often displays a fiery orange-red or yellow colour. While not technically correct, this variation of visual appearance with lighting is sometimes referred to as dichroism. The most famous example of a glass object displaying this optical property is the Lycurgus Cup in the British Museum which dates back to the Roman period. This paper examines the history of Renaissance Venetian chalcedoy glass, looks at recipes for such glass and undertakes chemical analysis of such.