What does it mean when a 1924 peace dollar has s a stamped into the obverse?

Answer 1

If you mean the REVERSE, that's the mint mark. It tells what Mint struck the coin. In your case it means it was struck in San Francisco; that makes it worth about $20-22 in moderately worn condition. If you are referring to the front of the coin, it's a counterstamp that was added by someone using a metal punch. That makes your coin a damaged piece worth only about $14 for its silver content.

Very often a coin's mint mark will have a major effect on its value, because each mint may have struck a very different number of coins. Philadelphia and Denver are the only 2 mints currently making coins for circulation, but other mints have operated in:

San Francisco - "S"

New Orleans - "O"

Charlotte - "C"

Dahlonega, GA - "D" (but it closed long before Denver opened)

Carson City - "CC"

San Francisco now makes only proof coins, and a new mint was opened at West Point to make commemorative coins. It uses "W".

Philadelphia coins did not have mint marks for all of the 19th and most of the 20th centuries, so there is nothing wrong if you find an old coin without a mint mark. That just means it came from Philly. The P mint mark was first used on nickels from 1942 to 1945, then on dollars starting in 1979, and all other coins except cents starting in 1980.