Yellowcake is a concentrated form of uranium oxide (U₃O₈) produced during the milling of uranium ore, and it serves as an intermediate step in the production of nuclear fuel. Yellowcake is significant in economic geology and the nuclear industry for its role in the nuclear fuel cycle, from mining to reactor use.
Reference: Emsley, J. (2011). “Nature’s Building Blocks: An A-Z Guide to the Elements.” Oxford University Press.