If you are referring to UK pennies, then most have no mint mark as they are produced at the Royal Mint. However, mint marks since the 1870's are either an H under the date or an H or KN to the left of the date.
However, I suspect you might be referring to US cents. In this case you will find the mintmark under the date, unless it is the Philadelphia Mint which does not place mint marks on cents, although "P" has appeared on all other denominations since 1980.
By far it is the penny.
Cents struck at the Philadelphia mint don't have a mint mark.
100.000.000
it was made in denver, at the denver mint
The coin likely has been altered outside of the US Mint. Error coins need to be seen, take it to a coin dealer, but don't expect to be offered anything for the coin.
A 1990 penny black anniversary stamp can be worth five dollars or more. The specific price will vary depending on the rarity of the stamp on the time of sale and condition.
The coin has been altered and has no collectible value. This is not an Mint error.
Mint MARK rather than "stamp", and it's the same on all circulating US cents:No mint mark = PhiladelphiaD = DenverS = San Francisco (only on older circulation coins, and on proofs made since 1968)
Here's a picture of the earliest English half-penny stamp. There were probably others later. http://www.stampwants.com/Great-Britain-58-Mint-OG-Fine-Sound-Plate-11-CV-110_QQitemnameQQ2836088QQidQQauctiondetails
There isn't any stamp that is called a penny purple. You need to describe the stamp - include country and if you can date and what is on the stamp.
No mint mark simply means it was minted in Philadelphia. It's not a rare coin, and is currently worth about 5 cents.
There isn't any stamp that is called a penny purple. You need to describe the stamp - include country and if you can date and what is on the stamp.
There is usually one up for auction at stamp auction sites. Most stamp stores would have some to sell. The mint ones are much more expensive than the used ones and they vary widely in condition since they are so old.
If a penny has no mint mark, it typically means it was produced by the Philadelphia Mint. Mint marks indicate where a coin was minted, and coins from the Philadelphia Mint, the oldest U.S. Mint facility, do not have a mint mark.
The value of the 1910 1955 penny stamp value is one pound.
The term is actually mint MARK, and cents without a mint mark are from the Philadelphia Mint. That's true even for current-date cents although Philadelphia has used a "P" mint mark on all other denominations since 1980. Please see the Related Question for more information.
British