David it looks to me like a coin weight(Medieval)or an apothecary weight
which would make it Post Medieval, copper alloy. It's actual denomination
I'm not sure of but a little bit of searching should find it!
From: British archaeology discussion list [mailto:[log in to unmask]]
On Behalf Of David Hayward
Sent: 27 January 2010 19:48
To: [log in to unmask]
Subject: [BRITARCH] Mystery Object
One of the membrs of our society recently found an unusual object which to
date has not been positively identified, it is about 2 cm sq and made
possibly of bronze, not lead, as it feels fairly heavy a photograph of it is
available at the following link: - www.claspweb.org.uk follow the link on
the front page to mystery object. The item is scheduled to be taken to the
local FLO but any initial thoughts would be appreciated.