Ewingite is a complex hydrous uranyl carbonate mineral of magnesium and calcium. Its chemical formula is . It was discovered by Jakub Plášil of the Institute of Physics at the

Academy of Sciences of the Czech Republic The Czech Academy of Sciences (abbr. CAS, , abbr. AV ČR) was established in 1992 by the Czech National Council as the Czech successor of the former Czechoslovak Academy of Sciences and its tradition goes back to the Royal Bohemian Society of ...

in the Plavno mine,

Czech Republic The Czech Republic, also known as Czechia, and historically known as Bohemia, is a landlocked country in Central Europe. The country is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the south ...

. Travis Olds of the

University of Notre Dame The University of Notre Dame du Lac (known simply as Notre Dame; ; ND) is a Private university, private Catholic research university in Notre Dame, Indiana, United States. Founded in 1842 by members of the Congregation of Holy Cross, a Cathol ...

and colleagues described ewingite, which is the most structurally complex known mineral on Earth. Ewingite is named in honor of

Rodney C. Ewing Rodney Charles Ewing (September 20, 1946 – July 13, 2024) was an American mineralogist, a materials scientist and a nuclear safety expert whose research was focused on the properties of nuclear materials exposed to radiation and long-term geoc ...

, Professor of Geological Sciences at Stanford University, USA. The mineral is rare, due to its very narrow pH and compositional range required for formation, which are only known to occur in the Plavno mine. Ewingite forms through

uranium Uranium is a chemical element; it has chemical symbol, 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. Ura ...

oxidation Redox ( , , reduction–oxidation or oxidation–reduction) is a type of chemical reaction in which the oxidation states of the reactants change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is ...

occurring in the humid environment of the mine. The mineral is chemically similar to rabbittite, swartzite, and

albrechtschraufite Albrechtschraufite ( IMA symbol: Asf) is a very rare complex hydrated calcium and magnesium-bearing uranyl fluoride carbonate mineral with formula Ca4Mg(UO2)2(CO3)6F2·17H2O. Its molar weight is 1,428.98 g, color yellow-green, streak white, densi ...

. The

type specimen In biology, a type is a particular wikt:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally associated. In other words, a type is an example that serves to ancho ...

of ewingite has been placed in the mineralogy collections at the

Natural History Museum of Los Angeles County Nature is an inherent character or constitution, particularly of the ecosphere or the universe as a whole. In this general sense nature refers to the laws, elements and phenomena of the physical world, including life. Although humans are par ...

Localities

: Plavno mine, Jáchymov District, Krušné Hory Mountains,

Karlovy Vary Karlovy Vary (; , formerly also spelled ''Carlsbad'' in English) is a spa town, spa city in the Karlovy Vary Region of the Czech Republic. It has about 49,000 inhabitants. It is located at the confluence of the Ohře and Teplá (river), Teplá ri ...

Region,

Bohemia Bohemia ( ; ; ) is the westernmost and largest historical region of the Czech Republic. In a narrow, geographic sense, it roughly encompasses the territories of present-day Czechia that fall within the Elbe River's drainage basin, but historic ...

References

Calcium minerals Magnesium minerals Uranium(VI) minerals Uranyl compounds Carbonate minerals Hydrate minerals Tetragonal minerals {{Carbonate-mineral-stub