What are all the combinations on eras of alchemy?

Alchemy is typically divided into three main eras: the ancient era, which includes Hellenistic and Egyptian influences; the medieval era, characterized by Islamic scholars and European alchemists like Paracelsus; and the modern era, which transitioned into chemistry. Each era reflects a shift in focus from spiritual and philosophical concepts to empirical and scientific approaches. Additionally, alchemical practices varied geographically, leading to regional combinations such as Chinese alchemy, which emphasized medicine and longevity, and Western alchemy, which often sought the transmutation of metals. Overall, the combinations of these eras showcase the evolution of alchemical thought and practice across cultures and time.