Wasn't looking for a way to fix this, just reporting a bug. I used the sorc options to reveal what the book was. The last sorc option was to basically give the book a magical zanax. Never read it by selecting the turn page options, so didn't learn speak with dead. I chose these class options, the book is the only artifact in the party, Gale says I have something already but no option to give it to him.
So have you found the gem and been able to open the book? IIRC you can’t give it to Gale (or Astarion who wants it for a different reason) until you’ve completed the relevant quest.
