Kruťaite, simplified Krut'aite or krutaite, is a rare

mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2011): Mi ...

with the formula Cu Se₂. It crystallises in the

cubic crystal system In crystallography, the cubic (or isometric) crystal system is a crystal system where the unit cell is in the shape of a cube. This is one of the most common and simplest shapes found in crystals and minerals. There are three main varieties o ...

. It is part of the

pyrite group The pyrite group of minerals is a set of cubic crystal system minerals with diploidal structure. Each metallic element is bonded to six "dumbbell" pairs of non-metallic elements and each "dumbbell" pair is bonded to six metal atoms. The group is n ...

, being composed of Cu²⁺ ions and Se₂²⁻ ions. The mineral is most often found as a dark grey aggregate consisting of tiny crystals no more than a millimeter in size. The crystals are opaque in any size.

Etymology

Kruťaite was first discovered in Petrovice in Okres Žďár nad Sázavou,

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 ...

and described in 1972 by Zdenek Johan, Paul Picot, Roland Pierrot and Milan Kvaček. It was named after Tomáš Kruťa (1906–1998), a Czech mineralogist and director of the mineralogical laboratory of the Moravian museum. The

International Mineralogical Association Founded in 1958, the International Mineralogical Association (IMA) is an international group of 40 national societies. The goal is to promote the science of mineralogy and to standardize the nomenclature of the 5000 plus known mineral species. ...

's rules on naming newly recognized minerals specify that a mineral name derived from a person's name should be

capitalized Capitalization ( North American spelling; also British spelling in Oxford) or capitalisation (Commonwealth English; all other meanings) is writing a word with its first letter as a capital letter (uppercase letter) and the remaining letters in ...

and preserve any

diacritic A diacritic (also diacritical mark, diacritical point, diacritical sign, or accent) is a glyph added to a letter or to a basic glyph. The term derives from the Ancient Greek (, "distinguishing"), from (, "to distinguish"). The word ''diacrit ...

s from the person's home language (or its

romanization In linguistics, romanization is the conversion of text from a different writing system to the Latin script, Roman (Latin) script, or a system for doing so. Methods of romanization include transliteration, for representing written text, and tra ...

). Thus, the older spellings ''krutaite'' and ''Krutaite'' are deprecated in favour of ''Kruťaite''. In

Czech orthography Czech orthography is a system of rules for proper formal writing (orthography) in Czech. The earliest form of separate Latin script specifically designed to suit Czech was devised by Czech theologian and church reformist Jan Hus, the namesake of ...

, when a ''

háček A caron or háček ( ), is a diacritic mark () placed over certain letters in the orthography of some languages, to indicate a change of the related letter's pronunciation. Typographers tend to use the term ''caron'', while linguists prefer ...

'' (◌̌) modifies a lowercase t, it has a reduced ''klička'' form (as ť) which looks like an

apostrophe The apostrophe (, ) is a punctuation mark, and sometimes a diacritical mark, in languages that use the Latin alphabet and some other alphabets. In English, the apostrophe is used for two basic purposes: * The marking of the omission of one o ...

Occurrence

Kruťaite forms through hydrothermal processes and is often associated with

clausthalite Clausthalite is a lead selenide mineral, PbSe. It forms a solid solution series with galena PbS. Occurrence It occurs in low-sulfur hydrothermal deposits with other selenides and in mercury deposits. It is associated with tiemannite, klockmann ...

, eskebornite,

berzelianite Berzelianite is a rare copper selenide mineral with the formula Cu2 Se. It occurs as thin dendritic crusts or as fine-grained inclusions. It crystallizes in the isometric system, unlike its dimorph, bellidoite, which crystallizes in the tetra ...

uraninite Uraninite, also known as pitchblende, is a radioactive, uranium-rich mineral and ore with a chemical composition that is largely UO2 but because of oxidation typically contains variable proportions of U3O8. Radioactive decay of the uranium c ...

hematite Hematite (), also spelled as haematite, is a common iron oxide compound with the formula, Fe2O3 and is widely found in rocks and soils. Hematite crystals belong to the rhombohedral lattice system which is designated the alpha polymorph of . ...

ferroselite Orthorhombic ferroselite and its isometric polymorph dzharkenite are iron selenides of general formula FeSe2 precipitated under reducing conditions in anoxic environments. They are a source of selenium in the Rocky Mountains where selenium occu ...

bukovite Bukovite is a rare selenide mineral with formula Tl2Cu3FeSe4. It is a brown to black metallic mineral which crystallizes in the tetragonal system. It was first described in 1971 for an occurrence in the Bukov uranium mine, Rožná deposit, Vysoč ...

umangite Umangite is a copper selenide mineral, Cu3 Se2, discovered in 1891. It occurs only in small grains or fine granular aggregates with other copper minerals of the sulfide group. It has a hardness of 3. It is blue-black to red-violet in color with ...

chalcopyrite Chalcopyrite ( ) is a copper iron sulfide mineral and the most abundant copper ore mineral. It has the chemical formula CuFeS2 and crystallizes in the tetragonal system. It has a brassy to golden yellow color and a Mohs scale, hardness of 3.5 to 4 ...

and

goethite Goethite (, ) is a mineral of the diaspore group, consisting of iron(III) oxide-hydroxide, specifically the α- polymorph. It is found in soil and other low-temperature environments such as sediment. Goethite has been well known since ancient t ...

. It forms a

solid solution A solid solution, a term popularly used for metals, is a homogeneous mixture of two compounds in solid state and having a single crystal structure. Many examples can be found in metallurgy, geology, and solid-state chemistry. The word "solutio ...

series with

trogtalite Trogtalite is a rare selenide mineral with the formula Co Se2. It crystallizes in the cubic system and is part of the pyrite group, consisting of Co2+ and Se22− ions. It has a rose-violet colour and its crystals are opaque. It often occurs as ...

. It was first identified in Petrovice, Okres Žďár nad Sázavou,

, which is the only known locality in the Czech republic for the mineral, but it has since been identified in other places in the world. Notable is the El Dragón Mine,

Antonio Quijarro Province Antonio Quijarro is a province in the central parts of the Bolivian Potosí Department situated at the Salar de Uyuni. Its seat is Uyuni. Location Antonio Quijarro province is one of sixteen provinces in the Potosí Department. It is located bet ...

Bolivia Bolivia, officially the Plurinational State of Bolivia, is a landlocked country located in central South America. The country features diverse geography, including vast Amazonian plains, tropical lowlands, mountains, the Gran Chaco Province, w ...

, where crystals up to a millimeter in size have been found. Other localities include: Weintraube Mine, Lerbach, Rosenhof veins,

Clausthal-Zellerfeld Clausthal-Zellerfeld () is a town in Lower Saxony, Germany. It is located in the southwestern part of the Harz mountains. Its population is approximately 15,000. The town hosts the Clausthal University of Technology. The health resort is locate ...

Harz The Harz (), also called the Harz Mountains, is a highland area in northern Germany. It has the highest elevations for that region, and its rugged terrain extends across parts of Lower Saxony, Saxony-Anhalt, and Thuringia. The name ''Harz'' der ...

Lower Saxony Lower Saxony is a States of Germany, German state (') in Northern Germany, northwestern Germany. It is the second-largest state by land area, with , and fourth-largest in population (8 million in 2021) among the 16 ' of the Germany, Federal Re ...

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

. Tumiñico Mine, Sierra de Cacho,

Villa Castelli Villa Castelli is a ''comune'' in the province of Brindisi in Apulia, on the south-east Italy coast. It is a comune in Salento, the borderline with Itria Valley. Its main economic activities are tourism and the growing of olives and grapes. Main ...

, General La Madrid department,

La Rioja La Rioja () is an autonomous communities in Spain, autonomous community and provinces of Spain, province in Spain, in the north of the Iberian Peninsula. Its capital is Logroño. Other List of municipalities in La Rioja, cities and towns in the ...

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

. Yutangba Selenium deposit, Enshi Co.,

Enshi Tujia and Miao Autonomous Prefecture Enshi Tujia and Miao Autonomous Prefecture ( zh, c= , p=Ēnshī Tǔjiāzú Miáozú Zìzhìzhōu) is located in the mountainous southwestern corner of Hubei province, People's Republic of China. It forms Hubei's southwestern "panhandle", bordering ...

(E'xi Autonomous Prefecture),

Hubei Province Hubei is a province in Central China. It has the seventh-largest economy among Chinese provinces, the second-largest within Central China, and the third-largest among inland provinces. Its provincial capital at Wuhan serves as a major politi ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

References

{{Reflist Selenide minerals Copper(II) minerals

Etymology

Occurrence

See also

References