Before 1965 in most cases. While error coins can be found on any coin from the earliest coins to the present, all other coins that are valuable were minted before 1965. Any dime, quarter, or half-dollar minted before 1965 was minted in 90% silver making it worth more than face based on that only, no matter how common the year was.
There are a few explanations (if this truly is a mint error) The first and most valuable would be a quarter struck on a nickel blank, such a coin would be worth quite a bit of money. The second most valuable would be a coin that was a clipped planchet (blank) such a coin has a cut on it, but as this can be done after minting so it is best to see a coin dealer about this. But, it is always possible this wasn't done at the mint, but was done afterwards. So you need to see a reputable coin dealer to get it evaluated in person.
No they are not, in general just because a coin has a mintmark does not make it more valuable.
No, it's a novelty coin, manufactured specifically for people who want to know what the results will be when they flip a coin.
For an accurate assessment the coin needs to be seen by a coin dealer, some errors can be very valuable
The US 10 cent coin has president Roosevelt.
Penny
nope.
The most valuable US coin is the 1933 Saint-Gaudens Gold Double Eagle. In 2002 an example of this coin was sold at auction for 7.5 million dollars. At the time it was the most ever paid for any coin in the world.
The old South African 50 cent coin, particularly valuable, is the 1965 minting. This coin is sought after by collectors due to its lower mintage and historical significance. Additionally, the 1980 50 cent coin is also valuable, especially if it is in uncirculated condition. Coins from these years can fetch higher prices in the numismatic market.
August 1, 2009 There can be no doubt the most valuable US coin is the 1933 Saint-Gaudens Double Eagle. In recent years an example of this coin sold for over 7 million dollars.
No coins in 1949 are rare, but as with all US coins, high grade Mint State examples can be valuable.
After the abolition of the Guilder, the new most valuable coin would be the 2 Euro coin
Put a picture of the coin!
Oh, dude, that's an easy one. The letter "R" can change a dirty old coin into something valuable by turning it into a "dime." Like, it's not rocket science, just a little wordplay magic. So, next time you find a dirty coin, just add an "R" and watch the value soar... or not.
There is no doubt that the 1933 Saint-Gaudens Double Eagle is the most valuable US coin. One of these coins recently sold at auction for over 7 million dollars.
Ram darbar coin
any US coin site on the internet...............