The origin of large gypsum crystals in the Geode of Pulpí (Almería, Spain)
The Geode of Pulpí (Almería, Spain) is an ∼11 m 3 ovoid cavity, the walls of which are covered with meter-sized idiomorphic and highly transparent gypsum (CaSO 4 2H 2 O) crystals. We performed a thorough study based on field work, and petrographic and geochemical data collection, which aimed to reconstruct the geological history leading to …