Roman coins

A couple weeks ago I saw a coworker wearing a gold ring with an old coin set in the center.  The contrast between the shiny metal and the rustic, weathered coin instantly caught my attention so I asked about the history.  

The setting holds a Roman coin. He had lots of the old coins but the details were lost in layers of dirt and maybe rust.  He had tried to clean some with a wire brush and eventually brought out some of the detail but it took so long that the effort wasn't really worth the outcome.  I offered to try tumbling some for him to see if that would reveal some of the coin underneath but instead he insisted on bringing some for me to keep and use in my artwork (I tried to decline but only half-heartedly - what a fantastic opportunity!).  

All of the coins looked pretty much like this when I got them:

I tumbled them with stainless steel shot for about 30 hours and it really did get a lot of the muck off - here are the results:

I sent him pictures of how they came out and he sent a reply with more information:  They are from around 300 A.D. and the coins with the words "spes rei publicae" ("hope of the republic") probably date from the reign of the Roman emperor Constantine and his second wife, Fausta. They are copper. Constantine was the first emperor to convert to Christianity after he had a vision of Jesus. The coins often also carry the words "salus publicae"  ("salvation of the people") so there is a strong religious connection.

I love the way they came out and now just have to decide how to use them...