Using a UV light is always a good idea. I don't know if anyone else has noticed but there are now at least 3 variations of the current Riviera $1 chip. There are small, medium and large H&C UV marks on them. I spotted a variation when I was picking up my match play wins - one chip has a darker "R" on it than the others. Since I didn't know which I had at home I just took both of them.