The Stone of Hyperion was an emerald stone that allowed those who possessed it to see the true path of the Gods.
While in search of an exit, Kratos stood on a Pressure Plate in the middle of Olympus' Garden; and thus activated the stone in the statue and the one in Hera's Chalice, which they were both linked. The stone altered the view of the garden: steps that were too distant from each other now seemed connected. Paths formed where there were none. The stone also covered the screen in a green hue.
After he solved the garden's puzzle, Kratos crushed the stone from Hera's chalice, which broke the statue's effect once and for all.