Nautilus jewelry pendant silver - A Symbol of Natures Beauty. The key to the physics of the universe Plato The pendant is based on the structure of theNautilus shell. TheNautilus shellis one of the known shapes that represent thegolden meannumber. The golden mean number is also known as PHI - 1. 6180339. . . The PHI is a number without an arithmetic solution, the digit simply continues for an eternity without repeating itself.