Nanoscale Growth Mechanisms of Gypsum: Implications for Environmental Control of Crystal Habits
Year: 2026
Type: preprint
Abstract: Gypsum precipitation is a common process observed in diverse natural settings, offering valuable insights into (paleo)environmental conditions. It also holds significant industrial value, notably in wallboard production. However, its precipitation also poses severe challenges, for example, during water desalination. Despite numerous experimental and computational studies on gypsum since the late 19th century, the growth behavior and crystal habit remain poorly understood. In this work, we studied the nanoscale growth mechanisms controlling the formation of gypsum crystals from supersaturated solutions. We developed a method for obtaining oriented samples of natural idiomorphic gypsum crystals, enabling atomic force microscopy (AFM) imaging and microtopography characterization of all facets. Using this novel approach we (re-)examined the extensively studied {010} form, and, for the first time, the {120}, {-111}, and {011} forms. Remarkably, each form is dominated by a specific growth behavior, including cluster-mediated growth for {010}, stepped face growth for {120}, 2D nucleation and spiral growth for the {-111} form, and rough growth for {011}. These experimental findings differ from theoretical predictions, where all four forms are considered flat faces (F faces). We further demonstrate that the interplay between growth mechanisms of different forms, and the control that external factors exert on these, are the two key factors that dictate the crystal habit. Overall, this study establishes a framework for linking gypsum crystal morphology to the prevailing environmental conditions during growth. This understanding is critical not only for comprehending gypsum deposit formation in the geological record but also for the processing of advanced geomaterials and more effective anti-scaling strategies.
Source: ChemRxiv
Institutions: Centre National de la Recherche Scientifique, Institut de Recherche pour le Développement, Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux, AgroParisTech, Université de Lyon, Institut Lumière Matière, Federal Institute For Materials Research and Testing, BASF (Germany), Universidad de Granada, Consejo Superior de Investigaciones Científicas, Instituto Andaluz de Ciencias de la Tierra
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7162004172