The philosopher's stone is the legendary substance that turns metal into gold. Seek the philosopher's stone, find the philosopher's stone, the fabled philosopher's stone.
It was also supposed to grant eternal life, and the search for it occupied serious minds for centuries, Isaac Newton among them. The apostrophe is a misreading: the Latin phrase is the stone of the philosophers, plural.
1nounphilosopher's stoneThe legendary substance that turns metal into gold.
“The alchemist spent his whole life searching for the philosopher's stone.”
philosopher's stone is a substance.
A calque of Latin lapis philosophorum, the stone of the philosophers, misread in English as a singular possessive.
Latin
lapis philosophōrum
Middle English
philosophres ston
English, today
philosopher's stone
A misconstruction of philosophers' stone, from Middle English philosophres ston, a calque of Latin lapis philosophōrum.
Etymology from Wiktionary, CC BY-SA
Practised in Myths & Legends, Fairy Tales & Folklore