TCR only lists chips from the casinos of Nevada (plus a few Nevada non-casino chips). The chip you describe is probably just a home-game chip made for a private individual, or it could be a sample. The square-in-circle mold chips were sold primarily to cardrooms and individuals in the northwest, though a very few were used in Nevada casinos. If it is just stamped "CR" on both sides with no denomination, most likely it was for private use, or possibly a small cardroom that chose to use initials instead of a name on the hot stamp.