Years of research have been devoted to computer-generated 2D marbling, whereas 3D marbling has yet to be explored. The proposed mathematical marbling of 3D solids supports a compact random-access vector representation, creating solid marbling textures by composing closed-form 3D pattern tool functions. The resulting representation is feature-preserving and resolution-independent, and it consumes very little memory. To facilitate the solid-marbling texture authoring process, the authors also developed an intuitive user interface and a genetic algorithm.