CaUO2PO428H2O

CaUO2PO428H2O is a chemical compound, specifically a hydrated calcium uranyl phosphate. Its chemical formula indicates that it contains calcium (Ca), uranium in its uranyl form (UO2), phosphate (PO4), and water molecules (H2O) in a stoichiometric ratio of 28 water molecules per formula unit. This compound is a member of the autunite group of minerals, which are characterized by the general formula XY(XO4)2·nH2O, where X is typically a divalent cation and Y is a uranyl group.

In CaUO2PO428H2O, calcium acts as the divalent cation. The presence of the uranyl ion (UO2^2+) signifies that this compound is radioactive due to the uranium content. The phosphate anion (PO4^3-) forms the basic structural unit with the uranyl ion. The high number of water molecules (28) indicates that it is a highly hydrated salt, and these water molecules are incorporated into its crystal structure. Compounds with such high hydration can be sensitive to changes in temperature and humidity, potentially losing or gaining water.

CaUO2PO428H2O is also known by its mineral name, meta-autunite. It is a secondary uranium mineral, meaning it is often formed from the alteration of primary uranium-bearing minerals. It can be found in various geological environments, particularly in oxidized zones of uranium deposits. Its crystalline form is typically tabular or prismatic. Due to its radioactivity and chemical composition, it is of interest in the study of uranium biogeochemistry and as an indicator mineral in geological surveys.