Here is an error chip from Golden Nugget in Las Vegas: the $20 oversize baccarat with one black insert missing. Regular chip shown on the left is TCR N4459. The edge view shows that the slug of black clay is missing completely, not just squished to one side.

I believe both chips are standard Arc-Yellow from Paul-son; the error chip looks darker because it has table dirt on it.

I'd be interested in knowing if any other collectors have this error chip.