Medal

I've been offered a few strange gifts by parting students in my time, and we're supposed to refuse, but I couldn't offend my US student when he gave me this today. I'm not entirely sure what it is, but it's certainly interesting.

So, I've consulted with another graduate who is steeped in the US military and hear that "He gave you a coin! Collecting / exchanging coins is big in the US military.  Leaders give coins for a job well done, and soldiers / officers exchange coins at various events.  If you show up to an event without a coin and someone shows theirs, I think you end up buying the next round of drinks!"