The Formation of Calcium Sulfate From the Interaction Between Common Calcium‐Bearing Minerals and SO₂: Insights Into Mineral Stability on Venus

The elevated surface temperature (460°C) and pressure (95 bar) on Venus, combined with the harsh gases present in the atmosphere, provide a chemically active surface environment. This study exposed three calcium‐bearing minerals (calcite, anorthite, and wollastonite) to Venus's surface temperature and an atmosphere of 1.5% SO 2 in 98.5% CO 2 for three different lengths of time (6, 12, and 24 days). All three samples were coated with a continuous secondary layer of calcium sulfate within 24 days of exposure. All samples also exhibited concentrated nucleation sites on the surface, which contained larger crystals. Among the tested minerals, calcite developed the thickest layer of calcium sulfate, which is consistent with the literature, followed by wollastonite and then anorthite.