Alchemy – derived from the Arabic word al-kimia (الكيمياء, ALA-LC: al-kīmiyā’), is both a philosophy and an ancient practice focused on the attempt to change base metals into gold, investigating the preparation of the “elixir of longevity”, and achieving ultimate wisdom, involving the improvement of the alchemist as well as the making of several substances described as possessing unusual properties. The practical aspect of alchemy can be viewed as a protoscience, having generated the basics of modern inorganic chemistry, namely concerning procedures, equipment and the identification and use of many current substances.

Alchemy has been practiced in ancient Egypt, Mesopotamia (modern Iraq), India, Persia (modern Iran), China, Japan, Korea, the classical Greco-Roman world, the medieval Islamic world, and then medieval Europe up to the 20th century and 21st Century, in a complex network of schools and philosophical systems spanning at least 2,500 years.