I just have the bottom part -- the red, blue and yellow (3 poker chips, how nice!) Riviera part. It is a fob -- dictionary definition of fob:

"A small pocket at the front waistline of a man's trousers or in the front of a vest, used especially to hold a watch.

A short chain or ribbon attached to a pocket watch and worn hanging in front of the vest or waist.

An ornament or seal attached to such a chain or ribbon."

I guess it could be attached to a watch, key or something else. Or it could just be a good luck charm, as you say.

Robert