Abernathyite is a mineral with formula K(UO₂)(AsO₄)·3H₂O. The mineral is named after Jesse Evrett Abernathy (1913-1963) who first noted it in 1953 in the U.S. State of Utah. It was described as a new mineral species in 1956. Abernathyite is a transparent, yellow mineral that occurs as tabular crystals up to 3 millimeters (0.12 in). The mineral has a single perfect cleavage on (001). Abernathyite fluoresces yellow-green in longwave and shortwave ultraviolet. Because of its uranium content, the mineral is radioactive.