A naturally formed sandstone concretion from Fontainebleau, France, composed of exceptionally fine quartz sand cemented by silica. 59 × 60 × 22 cm (23 1/4 × 23 5/8 × 8 5/8 in.); 50 kg. Foaming Wave is a substantial 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, while the process through which they became cemented into sculptural formations occurred considerably later. Broad, rounded folds rise and curl across the formation, creating a complex arrangement of projecting lobes, recessed passages and softly modelled ridges. Its pale, finely textured surface emphasises the continuous movement of these contours. The title Foaming Wave draws attention to the formation’s swelling upper edges and layered undulations, which evoke the crest and suspended spray of a breaking wave. 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 irregular process. Variations in the movement of water and the intermittent deposition of silica produced the characteristic ridges, cavities and fluid outlines that distinguish each specimen. Despite its resemblance to modelled clay or carved stone, Foaming Wave is entirely unworked and formed by natural geological processes. 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 strong sense of movement, Foaming Wave occupies a compelling position between natural-history specimen and abstract sculpture. A detailed condition report is available upon request.