I was going through my change bucket when I found this dime. I am curious if it's an error, or just wear and tear. The dime is a little beaten up. The front of the dime is about 3/4 copper-colored, and the remaining 1/4 is silver. The rim has varying widths of copper/silver color (the copper band is much thicker in places than others, unlike other dimes, which seem have a pretty even band around). I am happy to answer any questions if I haven't provided enough information! Thanks (edited to add "silver color" since I am new to all this!)
Ithat's post mint damage (PMD) and there's no silver in it. Roosevelt Dimes post 1964 are 75% copper and 25% nickel http://en.wikipedia.org/wiki/Dime_(United_States_coin) as for the different thickness of the coin, I cant answer to that.
The coin is stained and damaged. It is worth 10 cents. I would spend it - but not in a machine because the damage may cause it to become stuck.
The planchet used to make this coin was punched out of a long strip of metal by what's called the "blanking press". The strip from which it is punched is made of three layers of metal bonded together with heat and high pressure. In the old days they actually used dynamite exploded above the sheets to fuse them. The dies simply shear the round planchet from the strip. As the die goes through it smears the top side of the sheet across the center. These outer sheets are quite thin. Depending on the sharpness and orientation of the shearing die the metal can be anywhere from not smeared at all to be very difficult determining which side of the coin or planchet was up when it was cut. It's quite normal to have a lot of variation here even from one edge of a coin to another. This date is worth about 50c in unc and has to be quite gem to get a good pre- mium. It is actually rather scarce in gem but the demand is low. It can be found in Proof Like with great effort.