Just starting to read this thread. This might have been mentioned but there is a stamping of sorts on most casino used chips. They, from my understanding, are to help casino personnel authenticate chips. Take your chips and look at them under a black light. Some might say the casino name or some sort of code name. Not that they are secret code names but they might be something of theme with the property. Luxor, I think, has a variety of them. They can also tell casino people what generation or issue the chips are from. When they order more chips, maybe they might change the markings. Thus they can separate out older chips from newer ones. A lot of the chips I have seen have had the simple hat and cane mark on them but then others did say the property name or some kind of logo from the property.