I Have A Dime Showing 85%-90% Copper On Reverse -

I'd hate to try and clean it, my opinion is not environmental -
- but that the planchet was "poured"? wrong.
Don't know how they layer them actually, but the features on the
reverse are very crisp in detail. Strike is very good -
you can see the copper very close to the reverse side when
looking at it from the side too.


Okay - weight of mint Roosevelt dime is 35.03 grains,
this one is 34.8 grains (weighed on jewelers scale)
- .05 difference in weight. Could be the real deal?



Here's a good starting point for it -

http://www.coinquest.com/cgi-bin/cq...ain_ct_id=90

Regarding planchet preparation, the US Mint does not use any molten metals at all so no pouring. Planchet metal stock in the form of massive sheet rolls is sourced from a commercial supplier. The CuNi clad alloy is a three layer metal sandwich bonded together. Bonding metal without welding or melting is a difficult proposition as you might imagine. To give you an idea of the brute force required for the task, the metal used to be bonded via a process known as explosion welding although I believe a different process is now used.

Beautiful pics BIO---thank you for posting a real example.
Calvin

Very interesting dime bio!