The grade of a roman coin does not take into account damage that the coin may have. Any damage should be described separately from the grade. Grades can also be referred to as + or - to describe being slightly better or worse than a particular grade (or the term approaching or aVF).
Extra Fine (EF). This coin has sharp details. You can even see the lines in the hair (The scan does not show this well).
Very Fine (VF). The coin has a full and easily read legend. Most of the detail of the portrait and reverse image is intact. Only a small amount of wear on the finest details.
Fine (F). The coin has wear but you can make out all or almost all of the legend.
Very Good (VG). You can see the legend and even read a small part of it. You should be able to identify a coin in this condition.
Good (G). You can see a portrait on the obverse and a person on the reverse. There are slight traces of letters but you cannot read them.
Fair (FR). If you can tell its a coin and not much else then it is in Fair condition. You can see a portrait on the Obverse and an animal on the reverse (probably a lion). There is not even a trace of any letters. This coin is a little better than some coins that would be rated Fair.
These coins were cleaned with Calgon and water in a
vibratory rock tumbler using BB's 3/4 full to get good tumbling action (gentle
and fairly safe). It takes 10 to 40 hours of tumbling to clean all the coins and
many fresh water changes. Some hand cleaning is still needed on many of the
coins. I tumble the coins for an hour initially with BB's and hot water only. I
inspect the coins every few hours and remove the ones that are mostly clean. I
use some hand cleaning methods between tumbling to remove the thicker layers of
encrustation and deposits. I also finish off with a soak in olive oil and some
detailing with a steel ruler edge and sometimes a needle. Tumbling by itself
will not clean all of the coins to their best condition. I find tumbling reduces
the amount of hand cleaning needed and makes the soaking stages more effective.
It
is possible to soak and brush and get similiar results but it will take much
longer and more effort. If you are only cleaning a few coins the expense of a
tumbler (around $90.00) is probably not worthwhile. If you tumble a coin for 40
hours and it is still like a rock you should use electrolysis and I do but only
on about 1 out of 10 coins. This grading page is my opinion but I did check
several other sources to see if I was being reasonable. Any comments are
appreciated.