[mormegil]

I am rereading, or listening to rather, the Fellowship on disc and a question has occurred to me I know not the answer.

What is the source of the magical power that Gandalf, Saruman, Radghast, Galadriel,Durin's Bane, Saruon and other possess? What can they do and how? We know Gandalf worked some lightning or some magic on Weathertop against the wraiths. He performed a sealing or locking spell on the door in the chamber of Marzbul, the lighting of the way by his staff. The balrog does a countr-spell against him at the door and it leaves him weary.

What 'magical' powers do each possess, how do they come across it and what is the power source of this magic?

Another example I just thought of is the girdle of Melian. Obviously most of the beings are maiar but not all, i.e. Galadriel and her mirror.