Gandalf: the Unilateral Coalition Builder

[Celuien]

Rattling around in the back of the barrow:

Why didn't Saurman take Narya? and Saruman the Ring-maker

And here you will stay, Gandalf the Grey, and rest from journeys. For I am Saruman the Wise, Saruman Ring-maker, Saruman of Many Colours!

Saruman could also have thought that he had Gandalf exactly where he wanted him. He probably was not expecting an escape, and told Gandalf that he would stay in Orthanc until the One Ring wa found. If Saruman took possession of the One, he wouldn't have a need to take Narya, since the One would give him control over all of the rings anyway, in addition to giving him all of the study sources he needed to perfect his own ring-making sklls.