This coin was being sold as a "Ancient Roman Coin" - The description mentioned that it wasn't silver, but assumed to be a bronze. I knew it looked like a denarius, but it looked bronze to me as well. Thought it may be some sort of mid-19th century replica. Got the coin in yesterday and it sure the heck is a silver denarius. A scarce type that was one of a series minted to commemorate Trajan's victory over the Dacians, and the annexation of Dacia to the empire.
The toning seems to be a brownish black color. Sort of like it may have been sitting in a cigar smoke filled room for years. I almost want to clean it, but the color is actually growing on me as I have no other denarii that quite looks like it.
Trajan, AR denarius, Rome. AD 111. IMP TRAIANO AVG GER DAC PM TRP, laureate head right, slight drapery on left shoulder / COS V PP SPQR OPTIMO PRINC, Victory, naked to hips, standing right, foot on rock, inscribing DA-CI-CA on a shield set on a palm stump. RIC 130; RSC 80; Strack 131; BMC 322; Sear 3128.
This is a better photo that depicts the brownish color.