I just picked up a couple of RR denarii, one of which is this denarius of M. Herennius. The obverse shows the divine personification Pietas. The reverse depicts the Catanian legend of Amphinomus and Anapias, who chose their elderly parents over gold when fleeing the volcanic eruption of Mt. Etna. Hard decisions, those Romans had to make. Any idea what causes surface roughness on some silver coins? Please share your coins of M. Herennius!
The rough surfaces is just probably mild corrosion (ie. leaching of impurities within the silver due to acidic soil) and/or maybe mild crystalization of the silver. Nothing to really worry about. It's a fantastic coin either way. Here's mine.
What @Sallent said about the mild corrosion/environmental damage. Looks pretty nice for having most likely been buried in the ground for nearly two millennia, right? Handsome coin.
I love this style of coin and the story it tells. The OPs coin is in good condition. One could easily start a sub collection with the field marks on the reverse.
