A rare and diseased jewel, a canker fallen from the heavens
Fist sized diamond made famous by the thief Tolky. Stole the ‘rock’ from the Archmage Olikan and made it famous when his hidden thief’s den was found and destroyed by Olikan. The rock was never found though and Olikan searches for it to this day.
There is a group that believes no good can come of trying to change to future to render a prophecy or prediction incorrect. They believe that meddling will either cause the prediction to be true in the first place, or make something worse or more extreme happen.