The site is a great source for information on "Metals Used in Coins and Medals by Tony Clayton. We found it while researching porcelain coins and medals.

This page details the various metals and alloys that have been used for coins and medals over the centuries.

When I was at University I gave a talk to the college Science Society on the subject, and it is also of interest to me as my first job involved carrying out research into alloys of such exotic materials as niobium, hafnium, tantalum, zirconium and titanium for superconducting, chemical and aeronautical applications.

We also had some gallium, but somebody left it above a radiator and it melted!

Some (but by no means all) of the information came out of 'The Teach Yourself Guide to Numismatics' by C.C.Chamberlain published in 1960, and I also wish to acknowledge the help of many correspondents on the newsgroup rec.collecting.coins.