Are you the official leader of the Thieve's Guild?
If you are asking me, then yes.
I am the leader of everything and, frankly, the richest person in the game. Lol... getting those stones and crown pretty set you up for life. Kind of makes the game boring in a way, though.
How much do you get for them? I never bothered collecting them all, but seeing that I have nothing else to do, I could search for them. Is it possible to sell them? I hope I didn't before I realized they weren't just 'Unusual Gems'.