philosopher's stone

A mythical alchemical substance that could allegedly transform base metals (most notably lead) into gold or silver. Depending on the source, it may also be a source of eternal life.

Examples

• The Philosopher's Stone plays a major role in the plot of Fullmetal Alchemist.

• One of Patchouli Knowledge's Extra-stage spell cards in Embodiment of Scarlet Devil is "Fire Water Wood Metal Earth Sign "Philosopher's Stone".