Although Paul Hegge does an excellent job posting all those Nevada scans that are linked to Greg's ChipGuide, it is still a work in progress.
With respect to the Luxor $1 chips there are seven different security codes. Security codes for the Luxor $1's are UV markings where a word is imprinted five times on each side of the chip, except for those that have no code imprinted. The codes are:
Nile, Pyramid, Tut, Egypt, Nile, Circus Circus and no code. These chips also appear with errors. It was not the intent of Chipco, but sometimes different codes appear on opposite sides. For example, Nile on one side and Pyramid on the other.
And just so you have the full story, if you noticed on Paul's site (Silver State Treasures) the first three Luxor chips were satin finish and the other two were linen finish. All seven security coded chips appear in both the satin and linen texture.
Therefore, there are 14 different variations of Luxor $1 chips. The Luxor is constantly replenishing their $1 chips. All re-ordered chips seem to be satin finish.
Of course whats really crazy about the security code, the $5 and $25 are not UV tagged.