Ring of Thrór

This Ring was unusual in that it was the only one of the Seven Rings of the Dwarves never to have been in Sauron's hands, at least until its capture in the late Third Age. According to tradition, it was passed directly by Celebrimbor to Durin III of Khazad-dûm, and so on to his descendants (the other six Rings were given to the Dwarves by Sauron himself). It was the last that Sauron captured, but its fate after this is not entirely clear: presumably Sauron would have kept it rather than destroying it, but even that can't be stated with certainty. At any rate, its power would have been eliminated with the destruction of the One Ring 174 years later.

The name 'Ring of Thrór' is, strictly speaking, a mistaken title. The general belief among the Dwarves was that Thrór had been its last bearer, and that it was lost in Moria when he was slain there. So, Glóin called it the 'Ring of Thrór' at the Council of Elrond, thinking that Thrór had been its last bearer. However, this was not so: in fact, Thrór had secretly passed it to his son Thráin, and it survived in Thráin's possession for many years after his father's death. Arguably, then, this Ring should be called the 'Ring of Thráin' rather than the 'Ring of Thrór'.