The water content can vary and small amounts of calcium, barium, magnesium, iron, and sodium are often present.

Carnotite is a bright greenish-yellow mineral that occurs typically as crusts and flakes in sandstones.

[7] Carnotite is reported in Congo (Kinshasa), Morocco, Australia (Radium Hill) and Kazakhstan.

[7] In Pakistan carnotite occurs in the Upper Miocene middle Siwaliks sandstone (Dhokpathan Formation), in the vicinity of Takhat Nasrati, Karak District.

[citation needed] The mineral was first described in 1899 by French scientists M. M. C. Freidel and E. Cumenge, who identified it in specimens from Roc Creek in Montrose County, Colorado, United States.