Sting (Middle-earth)
Sting has the magical ability to detect orcs or goblins nearby, glowing blue in their presence, as it did when the Fellowship encountered orcs in the mines of Moria. Tolkien establishes this as a common property of First Age Elf blades, particularly those forged in Gondolin. Sting is also exceptionally sharp. Bilbo manages to thrust it without effort deep into a wooden beam at Rivendell. Frodo also wounds a troll in Moria, after Boromir notches his own sword with his attempt. Sam uses Sting to cut through the giant spider Shelob's strong webs with ease, and also wound the spider, driving it away from the paralyzed Frodo.
One Ring
Frodo inherited the Ring from his uncle Bilbo Baggins. In Tolkien's earlier novel, "The Hobbit", Bilbo found the Ring in the caverns beneath the Misty Mountains. It had been lost in the caverns by Gollum, who used the invisibility it conferred to hunt orcs to eat. Gollum, a hobbit previously known as Sméagol, had kept the Ring for hundreds of years. He had murdered his friend Déagol to get the Ring shortly after Déagol found it in the river Anduin. Many centuries earlier the Ring had betrayed Isildur and fallen from his finger into the Anduin as he was eluding orcs—who killed him when he became visible. Isildur in turn had cut the Ring from the hand of Sauron, who had made the Ring and let much of his power flow into it. Sauron was the Ring's true master, and the only being who could bend it completely to his will.