Nero (Augustus) Coin: Bronze AS
NERO CLAVDIVS CAESAR AVG GERMANIC - Radiate head of Nero right
PONTIF MAX TR POT IMP P P - Nero, as Apollo Citharoedus, advancing right in billowing robes, playing lyre; mark of value I in ex.
Mint: Rome (64 AD)
Wt./Size/Axis: 6.87g / 23.01mm / 5 h
The D. Thomas Collection
Acquisition/Sale: Agora Auctions Internet Numismatic Sale #77
The I in the exergue is the mark of value.
Under Nero, the mint produced these brass asses on a weight standard of one half a dupondius. The letter I denotes one as, while II appears on dupondii equal to two asses and S appears on the semisses. This experiment with brass as was not continued by his successors, though some issued 3g brass semisses and Trajan and Hadrian produced brass 4g 1/3 dupondii and 8g 2/3 dupondii in the East.
From the Dictionary of Roman Coins:
Citharoedus Apollo. The Lyre-striking Apollo.-In this character Nero is represented on one of his first brass coins. "Another Apollo (as Suetonius observes), habited like the robed statues of the god, he appears walking, with the cithara in his left hand, and playing on it with his right.-Engraved in Dr. King's plates.