The philosopher's stone is a mythic alchemical substance capable of turning base metals such as mercury into gold or silver. It is also called the elixir of life, useful for rejuvenation and for achieving immortality; for many centuries, it was the most sought-after goal in alchemy. The philosopher's stone was the central symbol of the mystical terminology of alchemy, symbolizing perfection at its finest, divine illumination, and heavenly bliss. Efforts to discover the philosopher's stone were known as the Magnum Opus.
The Alchymist, in Search of the Philosopher's Stone by Joseph Wright of Derby, 1771.
Philosopher's stone as pictured in Atalanta Fugiens Emblem 21
The first key of Basil Valentine, emblem associated with the 'Great Work' of obtaining the Philosopher's stone (Twelve Keys of Basil Valentine).
Alchemy is an ancient branch of natural philosophy, a philosophical and protoscientific tradition that was historically practised in China, India, the Muslim world, and Europe. In its Western form, alchemy is first attested in a number of pseudepigraphical texts written in Greco-Roman Egypt during the first few centuries AD.
Depiction of an Ouroboros from the alchemical treatise Aurora consurgens (15th century), Zentralbibliothek Zürich, Switzerland
Ambix, cucurbit and retort of Zosimos, from Marcelin Berthelot, Collection des anciens alchimistes grecs (3 vol., Paris, 1887–1888)
15th-century artistic impression of Jabir ibn Hayyan (Geber), Codici Ashburnhamiani 1166, Biblioteca Medicea Laurenziana, Florence
"An illuminated page from a book on alchemical processes and receipts", ca. 15th century