What is Vandenbrandeite?
Vandenbrandeite is a rare copper uranyl hydroxide, usually green and associated with oxidised uranium deposits.
Mineralogy and structure
Reference formula: Cu(UO2)(OH)4. Vandenbrandeite is triclinic. The exact COD 9012785 model is used. Its uranium content makes it radioactive and copper-uranyl chemistry should not be inferred from green colour alone. Vandenbrandeite is classified with oxides and has triclinic crystal symmetry. Typical hardness is 3–4 on the Mohs scale and specific gravity is approximately 4.8–5.3.
Colour, lustre and habit
Typical colours include green, dark green, yellow-green, brown. The usual platy, tabular, crusty habit and vitreous, pearly, dull lustre help describe a specimen, but colour alone is not diagnostic.
Formation and notable localities
Vandenbrandeite forms in or is associated with secondary oxidation zones of uranium-copper ores, mine fractures and weathered primary uranium minerals. Important documented localities include the Musonoi Mine in the Democratic Republic of the Congo, France, Germany and other uranium districts.
Green uranyl chemistry in a copper-bearing mine
Vandenbrandeite is a high-interest cabinet mineral where vivid green colour and uranium geology meet. Secure presentation, locality and radiation information are part of the specimen's value.
Collecting and care
Radioactive and potentially chemically hazardous: keep sealed and shielded as appropriate, avoid dust and water, and follow local radiation-safety guidance.
