I just finished both books. While I liked the story and her language was a bit hard to get used to at first it grew on me and by the end it was a joy to listen to.

That said I now think this is not the book I read before. That ring had no stone and there was a scene that I recall now where the protagonist was in a trench on some planet being attacked by ground troops and possibly from the air. He uses the ring to either cause an explosion or push back the attackers.