Rings of Power talk!

[jallanite]

Originally Posted by Morthoron

Likewise, few even knew Gandalf had a Ring of Power, not even Saruman, who held him in captivity in Orthanc briefly.

From Unfinished Tales, Part Four, II The Istari:

And the Grey Messenger [Gandalf] took the Ring [from Cirdan], and kept it ever secret; yet the White Messenger [Saruman] (who was skilled to uncover all secrets) after a time became aware of this gift and begrudged it, and it was the beginning of the hidden ill-will that he bore to the Grey, which afterwards became manifest.

I am aware that Tolkien added this later and may not then have been considering carefully about whether Saruman knew that Gandalf bore the Red Ring when Gandalf was Saruman’s captive.