I take back what I said about all ivories were custom. The ivories that only had a ring on them were in most cases generic. However, once a custom, leaf, flower, number or animal was added to it at the request of a custom it became a custom chip. The chip in question is, as far as I know, is a one of a kind chip. The chances of that chip being a generic chip, where thousands upon thousands were made to be sold off the shelf to customers off the street are de minimis.