I used Goo Gone on a cheap chip that was spray painted. Q-Tip, lots of work and it didn't dissolve the chip. Still the same warning, test on something that doesn't matter first, in case it makes them soft. I also had some pine oil paint remover that someone was hyping as natural and all that. So I can't be positive which one, or both.

But take a look at Goo Gone at your local hardware store.

I never tried to remove a chip from Lucite (or whatever that stuff is?) But years ago there was a dentist who extracted some. Go figure, the guy has the tools, smarts and talent. If you watch any of the archaeology shows, they use a vibrating fine point tool, that chips away at the material that's stuck on the surface of fossil bones. They also use (wouldn't you know?) dental tools, with a sharp flat tip to flake off things. The idea is not scraping, but finding a platform and flaking off bits.

Not saying that's the answer, because sandstone or limestone is softer than a mineralized fossil bone. The trick would be chipping away the material if it hasn't bonded to the surface of the casino chip. Kind of like pressure flaking off little bits. I don't have the patience.