I work in retail so quite a few coins pass through my hands. A while back, I opened a roll of quarters and noticed one that looked different so I snagged it. It seemed like it was a different metal than usual and no copper layer was visible. It sounded different and felt different when I tapped it on a tooth. Interesting. Tonight I broke out my reloading scale and weighed it and discovered that it was a few grains heavier than other state quarters. This prompted me to look at it more closely and I noticed that it has an "S" mint mark. I just did a bit of poking around and found that the only quarters that came from San Francisco are the proof coins for sets. I imagine that this one was part of a set and either someone was hard up for cash or the set was given to a kid who opened it because he wanted to get a can of soda. Sadly, it's not in proof condition anymore. Are the proof coins made out of the same clad metal as the regular coins?

Indeed the proofs are made out of the same metal composition as the regular business strikes Wiley. That is, of course, unless they're silver proofs. Silver proofs will weigh more than regular clad issues. The absence of a copper layer may indicate that the coin was plated.

I did a bit more poking around and did a little math to convert from grains to grams and I believe that it is a silver proof. Interesting find but since it has been circulated, I'm sure that any value more than 25 cents has vanished. I'm not really a collector. More of an accumulator. If I find something interesting it goes into a box on my dresser. Handling as much cash as I do, I find coins from around the world that slip into our change supply. I snag them and toss them into the box. I wish I had found what the girl at Mrs. Fields found the other day. She showed me a coin and asked me if it was real money. It was an Indian head penny. No, I didn't get it from her. :-(

If it is indeed silver, then its current melt value is around $5 regardless of what kind of shape it is in. Not much numismatic value, but still a nice find in circulation.

"Proof" is not a condition, it is a method of production, one that is far more involved than standard, to produce a very strongly struck coin. So, your coin will always grade as a proof, just a lower grade proof having been circulated. The fact that it has about 5 bux in silver value alone at the moment has been pointed out. I would also point out that a circulated proof is VERY uncommon and that there are people that like the uncommon. So it has character to say the least, and a minimum of $5 value at the moment. Good find!

Wiley: Another thing to look for when handling large flows of money... Any bill with a seal that is colored other than green. The other colors are blue, yellow, brown, and red. A bill with a seal and serial number that is one of these colors is NOT automatically valuable, nor are all green seals automatically undesireable... It's just a really stand out way to watch for old bills. Seals of different colors start to stand out like sore thumbs when you simply realize they are out there.

Current melt value is close to 14X the value of the coin! Your correct, about the 25 cents! It is still worth more! Nice Find! Steve

Another good way to check your change is by simply lining your coins up like your going to roll them and check is any of them have a solid silver side (no copper visable). Then you can cross reference at a later time to see what the silver content is in that coin! This is the method i use when i search through my half dollar bags from the bank! Good luck!!

It sounds like someone decided to spend a silver proof quarter. Proof is a method of manufacture, not a grade, so the coin will always be a proof coin. The correct terminology for a circulated proof coin is an "Impaired Proof".

Do the Tissue Test. It works. Take the quarter, set it next to a known CLAD coin quarter. Lay a normal tissue over the two. If it is silver, it will be whiter and brighter than the known CLAD coin.

That is pretty cool. There was a white glow through the tissue. The difference in color is what caught my eye at first. It is so white that I thought that it was aluminum. An aluminum quarter would have been really cool. Silver never crossed my mind because, after all, we don't have silver quarters anymore. Right?

You can also tell by just looking at the edge of the coin. If it is silver, the edge is silver. If it is clad, it will be a shade of bronze.

I just found a 1999-S Pennsylvania Quarter. It is brighter and but has copper showing on the edge. The “S” is not very clear and in fact looks like a backwards 2. Also the rim relief seems to be higher than other Sate coins.