Hi. I guess this ancient coin is either a billon or silver. It weighs 3.4 g. Could you assist to identify it. Thank you.. Charles
I guess that the reverse could be Mars or Apollo. Please check that with others at CT. An average, well preserved denarius weight is 3.22 grams. You might look for your coin here: http://www.wildwinds.com/coins/ric/septimius_severus/t.html
3.4g is acceptable. The full reference for the coin is below: Septimius Severus AR Denarius. 197 AD. L SEPT SEV PERT AVG IMP VIIII, laureate head right / LIBERO PATRI, Liber (Bacchus) standing right, head left, holding thyrsos, right hand on head, crowning himself, panther at his feet. RIC 99; RSC 304. If your concerned about value, about $25-$30.
I'm not saying Mat is wrong but these come with several IMP dates on the obverse and this one is off center enough that it is only identifiable by style. I agree it is later so VIIII might be correct. Here are III and X. Early Liberes have a different pose.