The Atlantean necklace is an item from the graphical adventure game, Indiana Jones and the Fate of Atlantis (1992).
This necklace was created by Atlantean god-king Nur-Ab-Sal to hold his spirit within. Nur-Ab-Sal frequently experimented with misidentified alien technology resulting in him creating a race of human/alien hybrids in an attempt to achieve the status of a god. These creatures revolted against him leading to him transferring his soul into the necklace.
In 1929, the necklace was recovered in Iceland by the Jastro Expedition of archaeologists Dr. Jastro, Indiana Jones and Sophia Hapgood. Sophia would keep the necklace, causing the spirit of Nur-Ab-Sal to speak with her and lead her closer to finding the ruins of Atlantis. In 1939, she and Jones found Atlantis only for Nur-Ab-Sal's spirit to possess Sophia to use his ancient machines and turn him into a god through Sophia's body. Jones foiled these schemes however by throwing the necklace into lava, seemingly destroying it and Nur-Ab-Sal.
Through unknown means, the necklace or a replica of it survived into the 1950s where it was left in the town of Disney Springs, Florida at the bar of one Jock Lindsey. Jock was the aviator to Indiana Jones and a member of the Society of the Explorers and Adventurers and left the necklace in his bar's lost & found to be reclaimed by an unknown owner.