Chapter 24 offers an overview of Goethe’s geological output, a vast but somewhat understudied area of his work. It focuses in particular on Ilmenau, where between 1776 and 1796 Goethe supervised a mining project, and it argues that, despite the ultimate failure of the enterprise, the Ilmenau period was crucial in developing Goethe’s understanding of geological issues. The chapter also charts the course of Goethe’s geological work after the Ilmenau period, and it brings to light the geological references which pervade his literary work – including Faust and some of his best-loved poems.