* Mint State (MS) - never circulated: $400 - $1,200
* Uncirculated (AU) - minimum wear, may have slight surface marks: $250 - $750
* Extremely Fine (EF) - very slight wear, may have some light surface marks or hairlines: $150 - $500
* Fine (F) - moderate wear, may have visible scratches or nicks: $100 - $200
* Very Good (VG) - well-worn, may have significant scratches or nicks, but all major details are still visible: $50 - $100
* Good (G) - heavily worn, may have large scratches or nicks, but all major details are still visible: $20 - $50
* About Good (AG) - extremely worn, may have heavy scratches or nicks, but all major details are still visible: $10 - $25
As you can see, the condition of the coin is a major factor in determining its value. If you have a Mercury dime from 1900, it is worth having it professionally graded by a reputable grading service such as the Numismatic Guaranty Corporation (NGC) or the Professional Coin Grading Service (PCGS). This will help you ensure that you are getting a fair price for your coin.