Gypsum Crystal from the Qattamiya Area, Cairo – An Evaporitic Mineral Growth

This sample shows a well-developed gypsum crystal collected from the Qattamiya area in Cairo, Egypt, a locality known for its evaporitic sediments and surface mineralization. Gypsum (CaSO₄·2H₂O) commonly forms in arid environments where evaporation rates exceed water input, leading to the concentration and precipitation of sulfate-rich minerals.

The crystal structure preserved in this specimen provides valuable insight into evaporitic processes, groundwater chemistry, and the near-surface geochemical conditions that characterize the northern Eastern Desert. Such mineral growths are important indicators of paleo-environmental conditions and play a key role in interpreting sedimentary basin evolution.