The answer to this "mystery chip" is easy. It was minted the same time as the Plaza $2.00 chip. The Plaza is using the $2.00 but the $3.00 chip was only used for two weeks. The manager of the card room was trying to force a $5.00 by using the 2 & 3 chips. Needless to say the game never made it. They have been in the vault and can not be sold to the public. 13 tries and I still naven't gotten any yet.