When coins are bought or sold, one of the major factors that helps to determine the price is the grade or condition of the coin. As a general rule, coins that are in excellent condition and that have few if any defects will be more valuable than coins that are worn and have received a lot of wear and tear. Expensive coins should not be purchased unless graded by a reputable expert.
US coins are graded using two scales: the Adjectival Scale, which provides a general description of the coin, and the Sheldon Scale, which rates the coin on a 70-point numerical basis.
Regarding US coins, the following grades are among the most likely to be encountered by coin collectors (Roosevelt Dimes are used in the illustration).
Fair (FR) - coin is very badly worn. The kind of coin (type) can be determined, but there is no detail on raised design images (portrait is basically an outline). The date is barely visible and may not be entirely legible. Lettering barely visible and, near the edges, letters may merge with the rim. Equivalent to Sheldon Scale 2.
About Good (AG) - coin is very badly worn. The kind of coin (type) is apparent and the date is fully readable, but weak. Some lettering may not be fully legible. Letters near the edge may touch or merge with the rim. Raised design images have little or no detail (similar to those graded as "Fair"). Equivalent to Sheldon Scale 3.
Good (G) - coin is badly worn. Date and all letters are clearly legible. Letters near the edge may touch or merge with the rim. Raised design images show some weak details in places, but images are basically featureless. Equivalent to Sheldon Scale 4 to 5.
Very Good (VG) - coin is worn. Date and all letters are sharp and clear. Letters near the edge do not touch the rim. Rim is intact and full. Raised design images are worn and flat, but a few details will be visible. Equivalent to Sheldon Scale 8.
Fine (F) - coin shows some signs of wear evenly distributed over the surfaces. All letters and the date are sharply visible. Many details are visible in raised design images, though most details are weak. Equivalent to Sheldon Scale 12.
Very Fine (VF) - coin shows light to moderate wear, especially on highly elevated portions of the image. Equivalent to Sheldon Scale 20.
About Uncirculated (AU) - coin exhibits few defects. Lettering and raised design images are sharp. Very faint wear on the highest elevations. Retains some mint luster. Equivalent to Sheldon Scale 50.
Uncirculated (Unc) - Perfect or near-perfect specimen; coin has never been in circulation. However, coin may have slight scratches, dings, or indentations, caused by bumping against other coins in a mint distribution bag ("bag marks").