In Wolfram's text the Grail is a stone. 'Its name,' he declares, 'is lapis exilis,' which is one of the terms applied in alchemy to the philosophers' stone: 'the uncomely stone, the small or paltry stone'
Campbell demonstrates that Wolfram's deliberate identification of the Grail with the alchemical lapis exilis decouples the symbol from Christian sacramentalism and reorients it toward an interior, psychological-transformative significance.
, Creative Mythology: The Masks of God, Volume IV, 1968thesis