<P> Unlike the other Rings of Power, the One was unadorned . It bore only the inscription of the incantation Sauron spoke when he made it, and even that was invisible unless the ring was heated . Though the other rings could be destroyed in dragon - fire, the One could be unmade only in the unyielding fires of Mount Doom where it was forged . </P> <P> When Sauron made the ring, he was obliged to transfer much of his power into it so that it could control the other rings, themselves objects of great potency . With the ring, Sauron remained very powerful, and he could use it to dominate the will of others; he very quickly corrupted Númenor into the worship of Melkor and open rebellion against the Valar . </P> <P> When Isildur cut the ring from his hand, Sauron became much weaker . He required the ring to effect his conquest of Middle - earth, and spent most of the Third Age attempting to get it back . </P> <P> The ring had a great effect on the human bearers who held it in the interim . It granted them indefinite life; though the effort of living became more difficult as time went on, for it did not grant new life . If they wore it, it made them invisible, enhanced their hearing, and made the shadowy world of the wraiths visible to them . It exerted a malicious influence; Gandalf mentions that though a bearer might begin with good intentions, the good intentions would not last . The Ring would give its bearer a fraction of Sauron's power, proportionate with the bearer's strength and force of will . Gollum, Bilbo, Sam, and Frodo only became invisible, although when Frodo bound Gollum to his service in The Two Towers he indicated that he could use the Ring to control Gollum (because the Ring had mastered Gollum long ago). Gandalf and Galadriel, however, recognized that they could use the full power of the Ring, becoming even more powerful than Sauron himself, but they resisted, knowing that in the end the Ring would corrupt them . Gandalf explained to Frodo that, with great concentration and training, even he could tap into the Ring's power, but probably at the cost of his sanity . </P>

Three rings for the elven kings under the sky