The New Copper Metal Clay

http://www.riogrande.com/default.aspx

UK stockist:

http://www.silverclay.co.uk/shbr.htm

Hadar Jacobson's metal clay powders:

http://store.artinsilver.com/coclpo1.html

flickr copper clay photostream:

http://www.flickr.com/search/?q=copprclay&w=all