A naturally formed sandstone concretion from Fontainebleau, France, composed of exceptionally fine quartz sand cemented by silica. Mounted on a metal base; 40 × 30 × 15 cm (15 3/4 × 11 3/4 × 5 7/8 in.); 10 kg. The Walker is a compact and distinctly anthropomorphic example of the sandstone concretions known as Gogottes, found within the exceptionally pure sands of the Fontainebleau region in northern France. These sands were deposited during the Oligocene Period, approximately 30 million years ago, although the process through which they became cemented into sculptural formations occurred considerably later, during successive Quaternary glacial periods. The formation rises vertically through an arrangement of rounded projections, folded ridges and recessed passages. Its narrow lower structure appears to support a broader upper mass, suggesting a figure captured in motion. The pale, finely granular surface unifies these contrasting forms, while the asymmetrical silhouette creates a sense of balance and forward movement. The title The Walker draws upon this figural quality without imposing a fixed interpretation upon the natural formation. Gogottes developed as silica-rich groundwater circulated through the Fontainebleau sands. Dissolved silica precipitated between the exceptionally fine quartz grains, binding them together through a gradual and discontinuous process. Variations in water movement and the intermittent deposition of silica produced their characteristic ridges, cavities and fluid outlines. Despite its resemblance to modelled clay or carved stone, The Walker is entirely unworked. Fontainebleau sandstone formations have been admired as natural curiosities since at least the seventeenth century and were incorporated into several of the gardens at Versailles under Louis XIV. Their flowing, biomorphic forms have subsequently invited comparison with the sculpture of Jean Arp, Henry Moore and Barbara Hepworth. Combining geological rarity with a striking suggestion of human movement, The Walker occupies a compelling position between natural-history specimen and abstract sculpture.