Feruchemy is a magical system from the Mistborn series by Brandon Sanderson. It allows users, known as Feruchemists, to store attributes like strength, speed, or memories in special metal objects called metalminds. These attributes can be accessed later, enabling the user to enhance or diminish their abilities as needed. Feruchemy is distinct from other magic systems in the series, such as Allomancy, which involves consuming metals for immediate effects. Instead, Feruchemists must carefully manage their stored attributes, making it a strategic and thoughtful practice. This system emphasizes balance and the importance of time in utilizing one's stored powers.