Just started working on this coin..I see IMP CAESAR..I will be searching for any reference coin.. It's 3.17gr 17.2mm
Hint: You can read the four letters following IMP CAESAR fairly clearly: TRAI See if you can figure it out from there.
Portraits on Roman Imperial coins of the first couple of centuries are pretty easy to ID by portrait alone. It can get difficult later on, especially in the Constantine and later coins. Your coin's emperor is readily identifiable by portrait. Here are some pages with typical portraits of the emperors. I think you'll find it very helpful. After looking at hundreds (or thousands) of coins in a few days, you'll be able to identify the earlier emperors at a mere glance (there are exceptions, of course). Hmm... my favorite page for this no longer works. Here's one that will probably do the trick (easier than clicking each emperor's page in Wildwinds): http://www.romancoins.info/ImaginesImperatorumStart.html Of course, knowing how their names appear on coins helps, as does being able to interpret the sometimes odd engraving. Here's a page of a CoinTalk member's website listing typical obverse legends for Imperial coins (scroll down the page to get to the names): http://www.wnccoins.com/0022.htm