Anhydrite (calcium sulfate) growing on a calcite (calcium carbonate) crystal after reaction with a carbon dioxide-sulfur dioxide gas mixture.
Anhydrite (calcium sulfate) growing on the surface of a diopside crystal after reaction with a carbon dioxide-sulfur dioxide gas mixture.
Pyrite that is decomposing to pyrrhotite and iron oxides. Cross section of a reacted slice (pyrite – pyrrhotite – magnetite – maghemite – hematite)