Generios 15
From Tardis Wiki, the free Doctor Who reference
Generios 15 was the fifteenth planet of the Generios system. The planet was a giant red planet. It was visited by the Sixth Doctor with Melanie Bush, Banto Zame, and Sally-Anne Stubbins, who came to retrieve the largest diamond in all of time and space which was guarded by the Jelloid. (AUDIO: The One Doctor)