Rare Specimens Collection Amethyst Geode – Botryoidal Growth and Microcrystals - Height: 330 mm - Width: 180 mm- 7298 g

This geode comes from Uruguay, from the same Lower Cretaceous basalt cavities that gave rise to the most refined siliceous landscapes of South America. Here, however, the amethyst does not take the classic euhedral prism shape: it prefers to manifest through a compact botryoidal growth, dense with microcrystals, covering the inner surface like a mantle of light wine-colored solidified glass. The color—a faint garnet hue, almost like malva dust—is the result of the discreet yet constant presence of trivalent iron in the hydrothermal waters circulating within the cavity. However, the chromatic intensity is not evenly distributed: as often happens in Uruguayan geodes, the hue emerges in gradients, following the very history of silica precipitation. Every undulation, every botryoidal relief, tells of a change in temperature, a variation in solute concentration, a sudden pause in the hydrothermal flow. The outer base, a shell of multistratified agate, preserves the memory of the original basalt bubble: green and yellowish bands, sometimes oxidized, mark the chemical waves that preceded the entry of silica.