Where to have ingots tested?

I have what I believe to be almost pure tin ingots. Where could I have one tested? And what is the approximate cost to do so? Thanks in advance!

scrap yards, usually free if they know you. member BNE will do it, send a small ingot and he keeps the ingot and sends you the results.

I'll 2nd BNE. He wants a small BB size sample to test and ask for a pound of lead for payment. It doesn't have to be the same as your sample. I ask him for his preference and send some extra. He does this around his work responsibilities but is usually pretty quick.

BNE tests all my pewter for the price of 1lb of Pb or Sn or any casting alloy. Drop him a PM to see how busy he is and where to send it.

Thanks to everyone! I'll shoot BNE a PM.