I've found a piece of old glass in the spoil on a building site. How do I find out about it?

Question:It's very thick and looks black with gold flecks over and through it. When it's held to the light it shines yellowish.

Answers:
take a pic of it and contact antiques roadshow website and they should be able to help you or give you some info on it . the website is www.antiquesroadshow.com. good luck .