I got a 1968-S proof quarter in a coin lot. All the coins are mixed and unmarked. So I'm wondering, is the proof clad or silver? Is there a simple way to tell? I could post pictures a little later if they would help.
It should be clad, unless it was minted on a silver planchet by mistake (I've never heard of quarters as late as 1968 getting minted on silver though, have heard of some 1965's and 1966's, but those wouldn't be proofs). Look at the edge, if it's clad should see an obvious copper band. If it's silver, will be solid. Can almost guarantee it's clad, based on the date (if it's not you have an unheard of error! It should have been impossible for San Francisco to have any silver quarter planchets in 1968). San Francisco didn't mint any proof silver quarters until 1992 (not counting the bicentennials; they did mint 40% silver proofs and business strikes of those).
You can always weight it if you have a gram scale accurate to 1 decimal place which should do the trick. I'm sure the silver coins weigh heavier but not too sure of the weighs.
Slu,it is only $1/2 coins that are silver right up until 1970,that is in the Proof sets from 1965 onwards,apart from the commemorative silver $1 & those silver Proof State Quarters. Aidan.
