Ethereal Ring

The Ether Ring is a powerful magical item in Ultima VII. With the charged Ether Ring, it is possible to enter the Tetrahedron Generator in the dungeon Deceit.

After waking up Penumbra in Moonglow, she told the Avatar to get the Ether Ring from Lord Draxinusom, so that he/she could stop the disruption of the Ether. Sadly, Draxinusom had sold the ring to Martingo, the self-proclaimed Sultan of Spektran. Going there, the Avatar had to defeat a Stone Harpy to reclaim the ring. Returning it to Penumbra, she charged it with her magic. The Avatar then wore it in Deceit to enter the Generator and destroy it, after defeating the Ether Monster within it.

Most likely the Avatar returned the ring to Draxinusom after the Black Gate was destroyed.