Stones of Barenziah

 are gems in The Elder Scrolls V: Skyrim. It is initially regarded as an Unusual Gem. Finding one prompts a Miscellaneous Quest to be added to the Journal, saying that the player must appraise the gem before using it. Gems can be appraised by a few people; two of which are Maul in Riften and Vex, part of the Thieves Guild, also in Riften.

Note: Anyone in the Thieves Guild should be able to appraise the gem.

Upon getting it appraised, the player learns that 24 exist in total and that they are only valuable as a whole set. Most, if not all, are found in the extra jobs for the Thieves Guild. The reward for collecting all of these items is the perk, Prowler’s Profit.

Locations

 * 1) Solitude, Proudspire Manor: in the master bedroom, the property must be purchased by the player first.
 * 2) Solitude, Blue Palace: on the bedside table in Jarl Elisif's quarters.
 * 3) Thalmor Embassy: In Elenwen's Solar, in a bedroom (during or after the main quest "Diplomatic Immunity") Note: If you don't get this during the Diplomatic Immunity quest, the two easiest ways to return are by utilizing a glitch that involves getting a horse over the fence (walk through the front gate with your horse, go to the walkway to the left of the embassy, jump into the nearby tree, then quickly jump over the fence) or by performing a fully-upgraded Whirlwind Sprint Shout from a certain spot (Click to see video ). Otherwise, it is not possible to re-enter the embassy by legitimate means (However, PC users can use a console command and enter the courtyard of the embassy).
 * 4) Dainty Sload: on a table in the Captain's Quarters (ship is docked between Solitude Lighthouse & Solitude).
 * 5) College of Winterhold: shelf in Arch-Mage's quarters, where you can gain access during Under Saarthal quest.
 * 6) Yngvild: chamber behind the throne in throne room.
 * 7) Hob's Fall Cave - necromancer's sleeping area near the alchemy lab.
 * 8) Markarth, Treasury House: next to bed in the master bedroom.
 * 9) Markarth, Understone Keep: on a table in a locked left side room of the Dwemer Museum.
 * 10) Dead Crone Rock: on a makeshift altar in front of the Word Wall at the top of the final tower.
 * 11) Whiterun, Jorrvaskr (Companions): In Kodlak's bedroom.
 * 12) Whiterun, 1st room of the Catacombs inside of the Hall of the Dead: In one of the left wall crypts near a skeleton.
 * 13) Whiterun, Dragonsreach: in the Jarl's bedroom
 * 14) Rannveig's Fast: on a table near the watery prison.
 * 15) Fellglow Keep: on a counter in the workroom/workshop at the top of the front foyer (next to the alchemy lab).
 * 16) Windhelm, House of Clan Shatter-shield: Upstairs first bedroom on the left.
 * 17) Windhelm, Palace of Kings: on a table in Wuunferth the Unliving's quarters (the first door on the left side of the main hall, then at the end of the upstairs hall).
 * 18) Stony Creek Cave - in the Bandit Wizard's cavern.
 * 19) Ansilvund: near Fjori's ghost in the burial chambers.
 * 20) Sunderstone Gorge: on the alter in front of the word wall.
 * 21) Dark Brotherhood Sanctuary - on the dresser in Astrid's room. The stone can still be obtained after the Dark Brotherhood is destroyed.
 * 22) Pinewatch: Move through Pinewatch until you get to the Pinewatch Bandit Sanctuary. Once in the Bandit Sanctuary defeat 3 bandits in the first room before moving up the ramp on the right. In the next hallway defeat 1 bandit before moving up a flight of stairs. In the next room you will find empty Draugr tombs, directly to your right you will see a locked door. Lockpick this door and inside you will find the stone on the top shelf of the right bookcase.
 * 23) Riften, Mistveil Keep: in the Jarl's chambers.
 * 24) Black Briar Lodge, east of Riften: in the upstairs master bedroom.

Recovering the Crown of Barenziah
After handing in the 24 Stones of Barenziah, the Dragonborn is asked to recover the Crown of Barenziah from Tolvald's Cave. Vex reveals that the Crown of Barenziah is actually owned by a paragon for the Thieves Guild. Recovering the crown, she should be able to restore this paragon to its full strength.

Reward
After you have handed the Crown of Barenziah and the Stones of Barenziah to Vex and completed No Stone Unturned. She rewards the Dragonborn with the Prowler's Profit. Afterward, the fully restored Crown of Barenziah sits on the mannequin bust in the Thieves Guild.

Notes/Bugs

 * Fellglow Keep (PC/Xbox): For some reason, the gem may not appear on the counter it is supposed to be on.
 * Calixto's House of Curiosities (Xbox 360): If you have checked all 24 locations and are still missing a Stone, check Calixto's museum. Sometimes one can be found on the shelves here.
 * If you collect all the stones before having them appraised and identified they will stack under the name, Unusual Gem. After you get them appraised and find more, they will all be labeled "Stone of Barenziah, but be stacked in different versions.
 * If you collect all 24 stones before having them appraised, upon getting them appraised, the quest shows 25/24 and won't let you turn them in again. (Xbox 360). In other words, have them appraised before finding them all. Also, reloaded from previous save with 21 unappraised gems, turned them in and then quest showed I had 22. Seems to be adding one after appraisal. Recompleted quest with 23 gems (never took #21).
 * (PS3) While visiting Rannveig's Fast game bugged and would not let me grab Power Word. Upon droping down through the trap door and killing Sild the Warlock. I attempted to grab the Stone of Barenziah but it would not go into my inventory. After saving and reloading the stone was placed in my inventory along with the other ten stones I had but the quest log book stated I had 60/24 stones required for the quest. I was able to return to Vex at the Theives Guild to contine the quest line with only 11/24 stones in my inventory.