These pieces are bone. they are quite old French chips. The 20 and 2.50 are small...only a little over an inch wide. I bought them for the 2.50 chip. I like unusual stuff like that. All the chips, except the 2.50, have the denomination on both sides. The 2.50 is blank on the back side. In the little recessed circle on each chip is an engraved "B".