For the beginning collectors, I just wanted to start with a little background terminology first.

Terminology 

A raw coin is a coin that has not been slabbed by a grading service like PCGS, NGC, ANACS, SEGS, etc.  Buying a raw coin is always more risky than buying a slabbed coin.

Uncirculated coins are assigned an MS grade of MS-60 through MS-70.  MS stands for Mint State.  An MS-60 coin might be lacking luster and have a lot of blemishes.  An MS-70 coin is absolutely perfect and has no blemishes at all.  The higher the MS grade, the nicer the coin. 

Hairlines are very faint scratches.  If a coin has a lot of hairlines, it is possible the coin has been cleaned.  The old time albums with the plastic slides can also cause hairlines.  For example--a little piece of grit gets under the plastic and when the slide is moved, it pulls the grit along the coin and leaves a hairline.  If a coin has several hairlines that go in different directions, it was probably caused by an old time album or some other storage method.  If a coin has tons of these hairlines with the majority of them going in the same direction(s), the coin has probably been wiped/cleaned.

Advice and Questions to Ask

I do buy raw coins on E-bay and have gotten some really fantastic deals.  But you really need to be careful.  I see so many raw coins advertised as uncirculated coins, while in reality, they have wear or have been cleaned.

When buying coins, unless I know the seller really well, I always ask the following questions:

1. Does the coin have full cartwheel luster, including on all of the devices? For the beginners, if you take a new state quarter and tilt it while holding the coin under a light, the light seems to move in bands on the coin in a circular motion.  This is called cartwheel luster.  It is possible for a coin to be uncirculated and not have cartwheel luster.  But the coin will be at a lower MS grade.

2. Are there any scratches or hairlines on the coin?  Scratches and hairlines are usually damage that occurs outside of the mint.  It is important to note that hairlines do not always appear in the picture of a coin depending upon lighting and the resolution of the camera.

3. Has the coin been cleaned?  I kind of use questions 2 and 3 together.  If a seller tells me the coin has not been cleaned, but has lots of hairlines, I get suspicious and will not bid on the coin.

4. Does the coin have any spots or other detracting marks? I ask this to help make sure I'm not overlooking anything.  Maybe the coin has a light spot that does not show up in the picture or some other type of problem.

5. What MS grade do you estimate the coin to be?  I ask this if the seller does not specify a grade.  But a lot of sellers seem to over grade.  For example, a GEM BU coin is considered to be at an MS-65 or better grade.  But many sellers are calling an MS-64 coin a GEM BU.  I also see some sellers advertising a coin as MS-67 or MS-68 and it is no better than MS-63.  If I have an older coin that is an MS-67 or MS-68, no way would I ever sell it raw!!  I'd send it to NGC or PCGS and get it slabbed. 

6. Do you have a return policy?  If a return policy is not clearly stated and you are unfamiliar with the seller, always ask this question.  And save the seller's reply about the return policy until you receive the coin and inspect it.  If you are unsatisfied and the seller gives you a hard time about returning it, the seller's initial e-mail may be helpful if you need to file a dispute.

Also, I'll admit I've gotten some great deals from sellers who do not offer a return policy.  But I've also gotten stuck a few times when I first started buying raw coins on E-bay.

I know there are more questions I could be asking and if anyone has any suggestions, please let me know.  I'll continue to update this guide.

Thank you for reading.