Sampo

The Sampo is the likely true name of the item you obtain from Kolmisilmä at the end of the game in The Laboratory.

Uses
All of the uses of the Sampo either trigger one of the game endings, or the start of a New Game +, depending on how many Orbs of True Knowledge the player has collected.

Names of the Treasure
The Sampo has 14 different names in the game, depending on how many Orbs of True Knowledge you pick up before entering The Laboratory.

Trivia

 * The sampo is the name of a treasure of varying type in Finnish mythology and the Kalevala. Specifically in the Kalevala, it takes the shape of a handheld mill, which when cranked produces an unlimited amount of salt, flour and gold. In the Kalevala, the blacksmith Ilmarinen forges the Sampo for the northerner Louhi in exchange for her daughter's hand in marriage, but regrets this as his homeland suffers famine while the northerners lead easy lives. Ilmarinen, Lemminkäinen and Väinämöinen attempt to steal the Sampo, but the ensuing battle with Louhi causes it to shatter and fall to the bottom of the ocean. According to legend, the broken remains of the Sampo continue to spring forth treasures to this day.
 * While the game never explicitly tells you that the true name of the treasure is "The Sampo", it's the name that's referenced in the game files.
 * The name of the Sampo being "Amulet of Yendor" when the player has obtained 34 Orbs is a reference to the 1980 dungeon crawler Rogue, which codified the mechanics of and serves as the inspiration for all subsequent video games known as "roguelikes", including Noita. In Rogue, descending to the bottom of the dungeon to retrieve the Amulet of Yendor, then returning to the surface, is the player's ultimate goal and wins the game.
 * The act of completing the work, using the Sampo when it is named "Amulet of Yendor", at The Floating Island, which results in the player obtaining infinite health, is most likely a reference to NetHack's win state, known as ascension, where offering the Amulet of Yendor to the player's god at their high altar rewards the player with immortality and ascension to demi-godhood, winning the game.