block of glass (Eccleston Hill, St Helens.)

Any colour but as large as possible. Irregular in shape this is often referred to as "cullet" and would be some of the waste glass from the tank of molten glass in a glass factory after it had cooled. (As a student I worked at Ravenhead Glass in the hollidays and saw lots of interesting pieces discarded round the site.)

Please ask if I can give a better explanation!

Jeff