Stone of Barenziah: Rannveig's Fast
One of the 24 Unusual Gems. Vex in the Ragged Flagon names them once you are in the Thieves Guild.
- Stones of Barenziah – Whiterun Hold
Where to get it
In the cell block below the word wall: let the trapdoor in front of the wall drop you, and look beside the alchemy lab and chest.
Found in Rannveig's Fast.