There are five components of a coin to determine it's good or not:
Luster: This applies to how light reflects from a coin’s surface. It is impacted by microscopic lines in the design. Luster diminishes as the surface of the coin wears away.
Color: Both the natural hue of the metal and the vibrancy of any colorization in the coin’s design are important, like for the Toned Morgan Dollar. Chemical cleaning can alter both of these, lowering a coin’s quality.
Detracting marks: Obviously detrimental to a coin’s value, detracting marks come from improper handling or packaging. Fingerprints are considered detracting marks. To protect coins from these, it is important to avoid handling coins and using tight plastic holders.
Cleaning or mishandling marks: These occur when a coin’s surface is actually damaged due to cleaning, rubbing, or polishing. They can also be caused by “cabinet friction,” the faint rubbing away of a coin’s high points, caused by contact with an envelope or tray.
Eye Appeal: While this category sounds extremely subjective, it actually refers to the absence of carbon streaks, striking defects, vinyl damage, and a myriad of other factors that detract from a coin’s overall appearance.