Vault

The Vault is a location on the Airship in Infiltrating the Airship and in the Toppat Orbital Station in Completing the Mission.

Note that the Airship and the Orbital Station have their own vaults, each containing a priceless gem and some other valuable items.

In Jewel Baron, the Vault from the station also has a picture imitating the Ruby, likely a placeholder for the Toppats until they get the gem back.

Infiltrating The Airship
During the Pure Blooded Thief Pathway, the vault holds the Romanian Ruby. Henry Stickmin stole the ruby from this vault. The Ruby is a prime focus in this room while there are other treasures also in this room.

Completing the Mission
During the Jewel Baron pathway, the vault holds the Norwegian Emerald. It has two buttons:
 * Eject (Fail): launches the Emerald into Space.
 * Open: opens the barrier.

The vault looks more space themed with more spaces for items. Henry Stickmin managed to steal the emerald.

Items
These items from various references can be seen in the vault from ItA and CtM:

Vault from Infiltrating the Airship (Legacy)

 * Large boxes of components.
 * A red and a blue magic carpet.
 * A Gyroid from Animal Crossing.
 * A golden kayak with an oar.
 * A large pile of money bags.
 * A golden knight helmet.
 * The Romanian Ruby in the center of the vault.

Vault from Infiltrating the Airship (Remastered)
In Among Us
 * Scaramanga's Golden Gun from the 007 movie "The Man with the Golden Gun".
 * An Elite Energy Sword from Halo.
 * A Coin from Super Mario.
 * A Gyroid from Animal Crossing, a Dekkoid (a Mega Dekkoid to be exact) being the first kind that PuffballsUnited ever got.
 * The Stout Shako hat from Team Fortress 2.
 * A large version of a Coin from Super Mario.
 * An 1887 sawed-off shotgun from Call of Duty: Modern Warfare 2.
 * A purple jacket from PlayerUnknown'sBattleGrounds.
 * A Viking helmet and a golden top hat.
 * A large heap of gold that takes up a quarter of the vault.
 * The Romanian Ruby in the center of the vault.
 * Scout's face in a painting.
 * A long cat painting.
 * The Mona Lisa painting.
 * The American Gothic painting.
 * A Final Destination painting.
 * A painting similar to Window XP's Bliss.
 * A painting of a map
 * The starry night painting.

Vault from Completing the Mission

 * A golden Ak-47.
 * An egg-shaped Ming vase.
 * A silver brick.
 * An eyepatch (Possibly Big Boss's eyepatch).
 * An wood log.
 * A purple crewmate stuffie, required to get the Assemble The Crew medal.
 * Jimi Hendrix's guitar.
 * Something's first dollar, a reference to Mr. Krab's first dollar.
 * A Murder of Crows Vigor bottle from Bioshock Infinite.
 * A Super Star from Super Mario.
 * A purple potion, possibly not a reference at all.
 * A Golden Turd.
 * Nacho Libre's mask.
 * The ice key from Banjo-Kazooie.
 * A gold and silver bricks.
 * The Norwegian Emerald, which is the most valuable item that the Toppats have stolen.
 * A drawing of the Romanian Ruby, likely a placeholder to the Toppats since it has been stolen by Henry.
 * Dusty's Hat.
 * A Strawberry Clock from Clock Crew.