Pewter is a lead/tin alloy; modern pewter (britannia metal, american pewter, and other names) is mostly tin and antimony. It's soft enough to work and carve with something like a sharp handtool................
I have been following this thread with interest as I make scale
figures (hobby). How does one eyeball a pewter item from Goodwill or
a flea market. There are lots of discarded beer mugs and medallions
from these sources. The metal seems soft enough but does not tarnish
as in traditional lead based pewter. How does one tell if it is
aluminium instead of pewter.