The Master Stone:
The Master Stone of the Palantíri is a confusing item for historians in Middle-Earth. This is because there are potentially two of the stones that have this title. Also, none who are interested
now have access to either stone.
The first, and the lesser of the two Master Stones is the master of the seven stones that were brought to Middle-Earth. This stone was placed in Osgiliath under the Dome of the Stars. The Palantir of
Osgiliath was lost in the Anduin during the sack of the city.
However, the true Master Stone never left the Undying Lands. It is kept in the Tower of Avallónë in Tol Eressëa.
The Lord of the Rings
The Unfinished Tales
Gondor | Arnor | Osgiliath | Palantíri | The
Ithil-Stone | The Anor-Stone | The Stone of Orthanc | Tol Eressëa | The
Third Age of the Sun