Ring of Thror

The Ring of Thrór was the first of the Seven Dwarf-rings to be forged, and the last to be recovered by Sauron.
While Sauron himself gave the Dwarves their Rings of Power, this one was originally given to King Durin III of Khazad-dûm by Celebrimbor, and it remained in the line of the House of Durin for thousands of years.
The Kings of Durin's Folk proved resistant to the magic of the Rings of Power, as Dwarves are hard to tame and the thoughts of their hearts are hidden. The rings, used only for the gaining of wealth, amplified their wearer's natural skills and desire for dominion which made them greedy and exceedingly rich. It is said that the Seven Hoards of the Dwarves were gathered thanks to a magic Ring, before they were devoured by dragons.
This seems to be the case with the Longbeards who massed their wealth, but during the time of the King under the Mountain Thrór, Smaug descended on the Lonely Mountain and drove the Dwarves of Erebor into exile. Long after his kingdom's destruction, Thrór passed the ring to his son Thráin, who dwelt for many years as an exile from his ancient home.
At last, Thráin set out on an ill-fated quest to regain his kingdom, but he was captured by the spies of Sauron, and the Ring of Thrór was lost forever. Sauron took it from Thráin by force in the dungeons of Dol Guldur.
Many Dwarves, however, did not know the fate of the Ring, and thought that it was lost in Moria when Thrór was killed by Azog. It was thought that one of the reasons Balin wished to reclaim Moria was to find the Ring. In the Council of Elrond, Gandalf told Glóin that Balin would not find the Ring there, as it was given to Thráin and lost in Dol Guldur.
The Ring of Thrór does not appear itself, but is named as "Angya", and is called "Handórm" by the Dwarves. Gandalf believes it to have been destroyed in the downfall of Barad-dûr.