Aneth

Aneth was the home planet of the Anethans and was ruled by a monarchy. Hymetusite was one of the planet's resources. The Fourth Doctor mentioned having visited Aneth at some point in time and considered it a pleasant place. (TV: The Horns of Nimon)

Aneth was a neighboring planet of Skonnos (PROSE: Doctor Who and the Horns of Nimon) and was subjected under the Skonnan Empire until it collapsed. Several generations later, the Skonnans returned, demanding sacrifices of people and hymetusite which were given to the Nimon. (TV: The Horns of Nimon)