Albrechtschraufite (IMA symbol: Asf) is a very rare complex hydrated calcium and magnesium-bearing uranyl fluoride carbonate mineral with formula Ca<sub>4</sub>Mg(UO<sub>2</sub>)<sub>2</sub>(CO<sub>3</sub>)<sub>6</sub>F<sub>2</sub>÷17H<sub>2</sub>O. Its molar weight is 1,428.98 g, color yellow-green, streak white, density 2.6 g/cm<sup>3</sup>, Mohs hardness 2âÂÂ3, and luster is vitreous (glassy). It is named after Albrecht Schrauf (1837âÂÂ1897), Professor of Mineralogy, University of Vienna. Its type locality is Jáchymov, Jáchymov District, Kruà ¡né Hory Mountains, Karlovy Vary Region, Bohemia, Czech Republic.