The tra-lo-klee was the meditation stone of Sikar, the first oracle of the planet Vulcan, who could reportedly use it to see the future. A person who touched the tra-lo-klee foresaw the precise moment and circumstances of his or her death.

The tra-lo-klee was one of the treasures evacuated from Vulcan aboard the starship Le-Troska during the civil war in the time of Surak. Thousands of years later, the tra-lo-klee was found on Abigail, a moon of the planet Cathy in the Novak system, by a USS Enterprise landing party led by Commander Spock. According to one account of the event, Spock lost consciousness when he touched the tra-lo-klee but was revived by Sergeant Jerry Workman flicking the stone out of his hand. (TOS novella: The Vulcan Treasure)

Since The Vulcan Treasure takes place before TOS movie: Star Trek II: The Wrath of Khan, it is possibly his death in that film which Spock foresees.
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