Carnotite is a

potassium Potassium is the chemical element with the symbol K (from Neo-Latin '' kalium'') and atomic number19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmos ...

uranium Uranium is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium is weak ...

vanadate

radioactive Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is consi ...

mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2 ...

with

chemical formula In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, ...

K₂( U O₂)₂( VO₄)₂·3 H₂O. The water content can vary and small amounts of

calcium Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar ...

barium Barium is a chemical element with the symbol Ba and atomic number 56. It is the fifth element in group 2 and is a soft, silvery alkaline earth metal. Because of its high chemical reactivity, barium is never found in nature as a free element. Th ...

magnesium Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic ...

iron Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in ...

, and

sodium Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable ...

are often present.

Occurrence

Carnotite is a bright greenish-yellow mineral that occurs typically as crusts and flakes in sandstones. Amounts as low as one percent will color the sandstone a bright yellow. The high

content makes carnotite an important uranium ore. It is a secondary

vanadium Vanadium is a chemical element with the symbol V and atomic number 23. It is a hard, silvery-grey, malleable transition metal. The elemental metal is rarely found in nature, but once isolated artificially, the formation of an oxide layer ( pass ...

and

mineral usually found in

sedimentary rocks Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particle ...

in arid climates. In the United States it is an important ore of uranium in the

Colorado Plateau The Colorado Plateau, also known as the Colorado Plateau Province, is a physiographic and desert region of the Intermontane Plateaus, roughly centered on the Four Corners region of the southwestern United States. This province covers an area o ...

region of the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

where it occurs as disseminations in

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicat ...

and concentrations around

petrified In geology, petrifaction or petrification () is the process by which organic material becomes a fossil through the replacement of the original material and the filling of the original pore spaces with minerals. Petrified wood typifies this p ...

logs. It also occurs in the U.S. states of

Wyoming Wyoming () is a state in the Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the southwest, and Colorado to t ...

Colorado Colorado (, other variants) is a state in the Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the western edge of the ...

South Dakota South Dakota (; Sioux: , ) is a U.S. state in the North Central region of the United States. It is also part of the Great Plains. South Dakota is named after the Lakota and Dakota Sioux Native American tribes, who comprise a large po ...

Nevada Nevada ( ; ) is a U.S. state, state in the Western United States, Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. N ...

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...

, and

Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to its ...

. It also occurs incidentally in Grants, New Mexico, and

Carbon County, Pennsylvania Carbon County is a county in the Commonwealth of Pennsylvania. It is located in Northeastern Pennsylvania. As of the 2020 census, the population was 64,749. The county is also part of Pennsylvania's Coal Region and Northeastern Pennsylvania. T ...

.Mindat with locations
/ref> Carnotite is reported in Congo (Kinshasa),

Morocco Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to A ...

Australia Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. With an area of , Australia is the largest country by ...

(

Radium Hill Radium is a chemical element with the symbol Ra and atomic number 88. It is the sixth element in group 2 of the periodic table, also known as the alkaline earth metals. Pure radium is silvery-white, but it readily reacts with nitrogen (rather t ...

) and

Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbeki ...

. In

Pakistan Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's List of countries and dependencies by population, fifth-most populous country, with a population of almost 24 ...

carnotite occurs in the

Upper Miocene The Late Miocene (also known as Upper Miocene) is a sub-epoch of the Miocene Epoch made up of two stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch, which lasted from 11.63 Ma (million years ago) to 5.333 Ma. The ev ...

middle Siwaliks sandstone (Dhokpathan Formation), in the vicinity of Takhat Nasrati,

Karak District Karak District ( ps, کرک ولسوالۍ, ur, ) is a district in Kohat Division of Khyber Pakhtunkhwa province in Pakistan. It is situated to the south of Kohat District and on the north side of Bannu and Lakki Marwat districts on the main ...

Name and discovery

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 Montrose County is a county located in the U.S. state of Colorado. As of the 2020 census, the population was 42,679. The county seat is Montrose, for which the county is named. Montrose County comprises the Montrose, CO Micropolitan Statisti ...

.Robert J. Wright and Donald L. Everhart (1960) ''Uranium'', in ''Mineral Resources of Colorado First Sequel'', State of Colorado Mineral Resources Board, p.330-331. It is named for Marie Adolphe Carnot (1839–1920),

French French (french: français(e), link=no) may refer to: * Something of, from, or related to France ** French language, which originated in France, and its various dialects and accents ** French people, a nation and ethnic group identified with Franc ...

mining Mining is the extraction of valuable minerals or other geological materials from the Earth, usually from an ore body, lode, vein, seam, reef, or placer deposit. The exploitation of these deposits for raw material is based on the econom ...

engineer Engineers, as practitioners of engineering, are professionals who Invention, invent, design, analyze, build and test machines, complex systems, structures, gadgets and materials to fulfill functional objectives and requirements while considerin ...

and

chemist A chemist (from Greek ''chēm(ía)'' alchemy; replacing ''chymist'' from Medieval Latin ''alchemist'') is a scientist trained in the study of chemistry. Chemists study the composition of matter and its properties. Chemists carefully describe th ...

Uses

Carnotite is an ore of uranium. At times in the early 20th century, it was mined primarily for

radium Radium is a chemical element with the symbol Ra and atomic number 88. It is the sixth element in group 2 of the periodic table, also known as the alkaline earth metals. Pure radium is silvery-white, but it readily reacts with nitrogen (rat ...

or vanadium. The mineral was used to produce quack devices involving radioactive substances.

Related mineral species

Several related mineral species exist, including: margaritasite (( Cs,K, H₃O)₂(UO₂)(VO₄)₂·H₂O) and

tyuyamunite Tyuyamunite (pronounced tuh-YOO-ya-moon-ite) is a very rare uranium mineral with formula Ca(UO2)2V2O8·(5-8)H2O. It is a member of the carnotite group. It is a bright, canary-yellow color because of its high uranium content. Also, because of tyuyam ...

, (Ca(UO₂)₂(VO₄)₂·5-8H₂O).

References

External links