Currently the San Francisco mint only produces proof coins. Every so often someone breaks up a proof set (accident / theft / ignorance) and spends the coins for their face value. However, once circulated, a proof coin loses whatever premium value it had when it was in its sealed package.
Look at the edge. If it's copper-colored you have a clad coin made of copper-nickel. In this case you can certainly hang onto it as an interesting find, but it unfortunately doesn't have any extra value. If the coin is lighter in color than a normal quarter and doesn't have a reddish edge, you probably have a silver quarter from a premium proof set. Even after circulation, the silver in it would be worth around $3.
That depends on which state, and whether it is a silver or clad proof coin.
$42
There were no S-mint quarters struck from 1955 to 1967 inclusive and no US coins carried mint marks during the transition from silver to clad coinage in 1965-67.
From 1892 through 1916, the United States Mint produced the Barber Quarter. The value of a 1914 Barber Quarter is based on its mint state: For example, if the quarter is graded as good, it value is $6.00; however, if its mint state is in extra fine condition, the value is: $65.00.
This is a better date Barber quarter, retail values are $12.00-$186.00 for circulated coins in collectible condition and also depending on what grade the coin is. And mint state coins start at $690.00
A 1919 standing Liberty Quarter Dollar in good condition (G4) is worth: $40; if its mint state is MS60, the value rises to: $175.00. If there is an S or D mint mark at the bottom of the left-hand pillar (i.e. at Miss Liberty's right side) the value range is roughly $85 to $1200.
The Canadian RCMP quarter is from around the 1960's it is worth 25 cents in bad condition and $1.25 in mint condition.
A 1919 standing Liberty Quarter Dollar in good condition (G4) is worth: $40; if its mint state is MS60, the value rises to: $175.00. If there is an S or D mint mark at the bottom of the left-hand pillar (i.e. at Miss Liberty's right side) the value range is roughly $85 to $1200.
Depending on condition a "D" mintmark may be worth $5.00 an "S" $4.25
it costs about 95 cents if perfect condition
The Mint has never made gold quarters. If you have a gold quarter then it has been plated which destroys the numismatic value of the coin. Its value is 25 cents plus the value of the little bit of gold they used to plate it. Some chemicals can cause the quarter to turn different colors. This also does not enhance the value of the coin.
As of mid-2010 they're worth about $3.25 for their silver content but some dates and mint marks could be worth much more to a collector. Check for a mint mark under the bow of the wreath on the back (D, S, or nothing) and look for a previously-answered question in the formWhat is the value of a US quarter?for example, What is the value of a 1945 US quarter?
$20 if very worn $30 if moderately worn $60 if like new, with no mint mark or an "S" $90 if like new with a "CC" mint mark