Mint mark, not mint. The Denver mint is the facility in Denver where coins are struck.
In any case you'll need to post a new question with the coin's date. Cents have been made in Denver for 100 years.
It's not steel. Either:
1. it's plated - worth 1¢
2. it's been dipped in acid to remove the copper plating - 1¢ again
3. it was never plated by the mint - an error coin worth $75 to $100.
The only way to tell would be to have a dealer inspect it in person. But the betting is on the #1.
The mint did not make an official mint set in 1930, so I am not sure what you have. Please describe it more fully.
Circulated 1960 small dates from the Denver mint are worth about $0.25.
A 1999 Denver Mint penny is not worth appreciably more than other pennies. In most collections, this penny would only be worth one cent.
1¢ The Denver mint ("D") churned out over a billion of these coins.
a penny
D is the mint mark for Denver. Anything minted 1959-1981 is worth 2 cents for its copper content.
There is no such mint mark. The only mints to strike cents with mint marks are Denver (D) and San Francisco (S). See this link for values.
The value of a 1964 Denver penny can vary depending on its condition and whether it has any unique characteristics. In general, a circulated 1964 Denver penny is worth about 2 cents to a collector. If it's in mint condition, it could be worth more to the right collector.
It depends on the year and condition of the penny. If it is from any time in the 1950s or later, it is most likely worth nothing to collectors - so it is worth face value (1 cent). All the D means is that is is made in the Denver mint.
Unless it is in exceptional uncirculated condition, an average uncirculated 1957 Philadelphia mint cent has a value of about $12 and a Denver mint has a value of about $5.
Sorry the Denver Mint was not even built in 1820
It could not have been minted at the Denver mint. The Denver mint did not start striking coins until 1906.
It's worth exactly 1 cent.