They call most any kind of celluloid or plastic, "Bakelite" which was the material that they made the early electrical switch plates and non-conductors from. These chips are "Catalin", an early form of celluloid, made in the 20's & 30's. This is a nice set. Ones like this in a colored Bakelite rack (usually yellow, brown or red) sells for 300-500. This set should be worth at least 150.-200. in the wood chest.