This is a Chipco choken from Nevada. Metal coated with enamel or ceramic.

The B&G chips at the Palms are similar to Chipcos in appearance but not in manufacturing process. They are also larger than a standard 39 mm chip but I don't know if all B&G chips are larger. Gene will know. All currently produced chips have a manufacturer's name or symbol on them so it's easier than it used to be to id them.