CaUO22PO421012H2O

CaUO22PO421012H2O refers to a calcium uranyl phosphate hydrate with a composition that can be represented by Ca(UO2)2(PO4)2·nH2O, where the hydration number n is commonly in the range of 10 to 12. This formula places the compound in the autunite group of minerals, which are characterized by uranyl phosphate frameworks with water of hydration.

In composition, the mineral contains calcium cations, uranyl groups (UO2)2+, phosphate (PO4) units, and water molecules. The uranyl phosphate layers create a structured framework in which calcium and interlayer water balance the structure. The exact number of water molecules can vary, reflecting dehydration processes or differing formation conditions.

Ca(UO2)2(PO4)2 minerals form in oxidized zones of uranium-bearing ore deposits and phosphate-rich rocks, as well as in hydrothermal environments associated with uranium activity. They commonly occur with other uranyl minerals such as autunite, meta-autunite, and related phosphate-bearing species. Formation is favored by near-surface weathering and mineralogical conditions that concentrate uranium and phosphate.

Physical properties typical of this mineral include a yellow to yellow-green color and a crystalline habit that can be tabular or prismatic. The mineral is usually transparent to translucent with a vitreous luster and, like other uranyl-bearing minerals, is radioactive and may exhibit fluorescence under ultraviolet light.

Safety and handling considerations stem from its uranium content. Handling should follow appropriate radiological guidelines to minimize exposure, and materials should be managed to prevent dispersion of dust or ingestion.

See also: autunite group minerals, calcium uranyl phosphate minerals, uranyl phosphate minerals. References for mineral data include standard reference works and online mineral databases such as Mindat and the Handbook of Mineralogy.