I am not sure of the silver value, but it would be minimal on the dime I bought for $14. I paid exactly what the lady ask for it as she just wanted to leave and go home. It graded poor and damaged by PCGS standards, but authentic. I sold it a year later for just over $600 U.S. The dime was a 1916D Mercury. In it's condition the the date was readable and the mint mark, but most of the other marking were worn badly, or severely scratched. I would have never considered it for the silver content. Any silver that grades a Very Fine or better is generally what collectors are after. Some such as the 1916D Mercury Dime, is so rare the collector value is so far above the silver it is ridiculous. Others to watch for (not silver) is the 1922 (no mint mark) Lincoln penny. Very rare, I have only seen one in 45 years of collecting coins. The missing mint mark was from a worn die and the true numbers of them made are unknown. Graded Fine to Very Fine, and sold for $900 years ago. Most any Seated Dollar is highly sought after as well. Any of the Bust types from the 1800's I would keep for the Numismatic value. The only "coin" I would consider, is the American Eagle series and the like. Sold as a Dollar coin, but really not much more than a silver bar of 1 OZ. Any silver dollar marked with a (CC) or known as a Carson City silver dollar, I would keep. If you don't know the grade or values, I would keep it, until I could find someone who did. Coins for me aren't considered as silver value to often, but then I collect a few coins.
One other very rare example would be the gold coins from the Dahlonega Mint. Extremely rare and highly sought after by collectors. Minted from the mines near Dahlonega Georgia. I was present when a full set sold for $150,000 in cash several years ago, bought by a friend of mine, now dead, and donated to the Museum in Dahlonega. Also what is termed as (and I mean no offense to any one) Mormon Dollars. Also gold, and comes in varying currency amounts, ($5,$10,$50, etc.).
Extremely rare, and again highly sought after. There are so many examples is it is impossible to list them all here, just check with someone who knows these things and be on the safe side. I would hate to think I refined something worth possibly thousands of dollars.
