[Puddleglum]

It's a sundial.

[floridarolf]

If this coin was a jeton the flying saucer could also be a wheel with a broken axle as a sign for luck (in Germany we say broken glass brings luck) or bad luck.

[dennisw]

sundial

[demoRat watcher]

If it is a sundial, it would have 12 sections, not 16, right?

Those rivets look like wheel rivets.

[xm177e2]

It's a sundial.

Could it be a joke, putting a sundial in the position of the sun?