1948 Dollar - You Versus NNC

The luster looks "disturbed" that's how you can tell it's been cleaned....it's hard to describe, but if you were to see a cleaned coin vs non cleaned coin in person, you would see the difference. The clean coin may appear "bright" but it's dull compared to the natural silver luster after minting....also camera lighting may affect the appearance.

Abrasions are usually only evident on harshly cleaned coins. When you look at a 66 year old coin and it has no original patina it would be because of one of two possibility's. Either the coin has been cared for perfectly for the last 66 years, or, the surfaces have been altered in some manner. Now you can decide which possibility is more likely. With experience you will almost always be able to instantly detect if a coins surfaces have been altered or not, and this will help with your buying decisions and the coins value.