Jill,

Here is one that used to be in my collection until I upgraded.

It shows the same type of edge as yours does. It has never seen a 2x2 like the one you were using.

Mississippi Belle II in Clinton, IA had a similar .50 blue chip. I was there a couple times and 99% of them looked just like your chip does. I also remember that Casino Magic in Bossier City had the same problem with these chips.

Maybe Bud Jones had a plastics problem at one time or another?

Greg