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Krut'aite
Krut'aite or krutaite is a rare mineral with the formula Cu Se2. It crystallises in the cubic crystal system. It is part of the pyrite group, 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. It has no industrial use, but it is a prized collector's item. Etymology and history Krut'aite was first discovered in Petrovice in Okres Žďár nad Sázavou, Czech Republic and described in 1972 by Zdenek Johan, Paul Picot, Roland Pierrot and Milan Kvaček. It was named after the Czech mineralogist and director of the mineralogical laboratory of the Moravian museum, Tomáš Krut'a (1906–1998). Since Krut'a is officially spelled with a Ť, the mineral is written correctly as Krut'aite, according to the rules established by the IMA. In older publications, the apostrophe is omitted entirely. Occurrence Krut'aite forms through h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selenide Minerals
Selenide minerals are those minerals that have the selenide anion as a main component. Selenides are similar to sulfides and often grouped with them. Examples include: * achavalite * athabascaite * clausthalite * ferroselite * penroseite * stilleite * tiemannite * 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 ... References {{Mineral-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 . It has the same crystal structure as corundum () and ilmenite (). With this it forms a complete solid solution at temperatures above . Hematite naturally occurs in black to steel or silver-gray, brown to reddish-brown, or red colors. It is mined as an important ore mineral of iron. It is electrically conductive. Hematite varieties include ''kidney ore'', ''martite'' (pseudomorphs after magnetite), ''iron rose'' and ''specularite'' (specular hematite). While these forms vary, they all have a rust-red streak. Hematite is not only harder than pure iron, but also much more brittle. Maghemite is a polymorph of hematite (γ-) with the same chemical formula, but with a spinel structure like magnetite. Large deposits of hematite are found in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lower Saxony
Lower Saxony (german: Niedersachsen ; nds, Neddersassen; stq, Läichsaksen) is a German state (') in northwestern Germany. It is the second-largest state by land area, with , and fourth-largest in population (8 million in 2021) among the 16 ' federated as the Federal Republic of Germany. In rural areas, Northern Low Saxon and Saterland Frisian are still spoken, albeit in declining numbers. Lower Saxony borders on (from north and clockwise) the North Sea, the states of Schleswig-Holstein, Hamburg, , Brandenburg, Saxony-Anhalt, Thuringia, Hesse and North Rhine-Westphalia, and the Netherlands. Furthermore, the state of Bremen forms two enclaves within Lower Saxony, one being the city of Bremen, the other its seaport, Bremerhaven (which is a semi-enclave, as it has a coastline). Lower Saxony thus borders more neighbours than any other single '. The state's largest cities are state capital Hanover, Braunschweig (Brunswick), Lüneburg, Osnabrück, Oldenburg, Hildesheim, Salzgitt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harz
The Harz () 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'' derives from the Middle High German word ''Hardt'' or ''Hart'' (hill forest). The name ''Hercynia'' derives from a Celtic name and could refer to other mountain forests, but has also been applied to the geology of the Harz. The Brocken is the highest summit in the Harz with an elevation of above sea level. The Wurmberg () is the highest peak located entirely within the state of Lower Saxony. Geography Location and extent The Harz has a length of , stretching from the town of Seesen in the northwest to Eisleben in the east, and a width of . It occupies an area of , and is divided into the Upper Harz (''Oberharz'') in the northwest, which is up to 800 m high, apart from the 1,100 m high Brocken massif, and the Lower Harz (''Unterharz'') in the east which is up to aroun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 City is the location of the Clausthal University of Technology. The health resort is located in the Upper Harz at an altitude between 390 and 821 m above sea level. Geography Clausthal-Zellerfeld is located on the Upper Harz Plateau. The environment is less mountainous compared to most of the Harz, but only hilly. As a result, the immediate surrounding area is less wooded and there are more meadow areas. Scattered in and around Clausthal-Zellerfeld are numerous dams and streams of the Upper Harz Water Regale. The depression between Clausthal and Zellerfeld marks a natural "borderline". Southwest extends the "Small Clausthal valley". City districts * Altenau-Schulenberg im Oberharz (since 2015) * Buntenbock (since 1972) * Clausthal-Zellerfeld * Wildemann (since 2015) History Clausthal-Zellerfeld originally c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lerbach, Osterode Am Harz
Lerbach is a village of Osterode am Harz in Lower Saxony, Germany. It is based in the south-western part of the Harz mountains. People * Wilhelm Kolle Wilhelm Kolle (born 2 November 1868 in Lerbach near Osterode am Harz, died 10 May 1935) was a German bacteriologist and hygienist. He served as the second director of the Royal Institute for Experimental Therapy, succeeding its founder, the Nobel ... (1868-1935), bacteriologist and hygienist References Towns in the Harz Göttingen (district) {{Göttingen-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bolivia
, image_flag = Bandera de Bolivia (Estado).svg , flag_alt = Horizontal tricolor (red, yellow, and green from top to bottom) with the coat of arms of Bolivia in the center , flag_alt2 = 7 × 7 square patchwork with the (top left to bottom right) diagonals forming colored stripes (green, blue, purple, red, orange, yellow, white, green, blue, purple, red, orange, yellow, from top right to bottom left) , other_symbol = , other_symbol_type = Dual flag: , image_coat = Escudo de Bolivia.svg , national_anthem = " National Anthem of Bolivia" , image_map = BOL orthographic.svg , map_width = 220px , alt_map = , image_map2 = , alt_map2 = , map_caption = , capital = La Paz Sucre , largest_city = , official_languages = Spanish , languages_type = Co-official languages , languages ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 between 19° 21' and 20° 59' South and between 65° 46' and 67° 15' West. It borders Oruro Department in the north, Nor Lípez Province in the west, Sud Chichas Province in the southeast, Nor Chichas Province and José María Linares Province in the east, and Tomás Frías Province in the northeast. The province extends over 180 km from east to west and 225 km from north to south. Geography The province lies at the Uyuni salt flat. Some of the highest mountains of the province are listed below:BIGM map 1:50,000 6335-III Cerro Keucha Division The province comprises three municipalities which are partly further subdivided into cantons. Population The main language of the province is Spanish, spoken by 87%, while 74% of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 grains. It was thought to be dimorphous with hastite, but this was discredited in 2009. Hastite turned out to be the iron selenide mineral ferroselite. It forms a solid solution series with krut'aite. Occurrence Trogtalite was first found in 1955 in Trogtal quarry, Lautenthal, Harz Mountains, Germany, after which it was also named. It often occurs intergrown with clausthalite grains at this locality. It has also been found in the Musonoi Cu–Co mine, Kolwezi, Katanga Province, Congo and in Argentina, in Tuminico, Sierra de Cacho, and in Los Llantenes, La Rioja Province. It is often found together with clausthalite, ferroselite, bornhardtite, native selenium, gold, and oosterboschite. See also * List of minerals This is a list of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solid Solution
A solid solution, a term popularly used for metals, is a homogenous mixture of two different kinds of atoms in solid state and have a single crystal structure. Many examples can be found in metallurgy, geology, and solid-state chemistry. The word "solution" is used to describe the intimate mixing of components at the atomic level and distinguishes these homogeneous materials from physical mixtures of components. Two terms are mainly associated with solid solutions - ''solvents'' and ''solutes,'' depending on the relative abundance of the atomic species. In general if two compounds are isostructural then a solid solution will exist between the end members (also known as parents). For example sodium chloride and potassium chloride have the same cubic crystal structure so it is possible to make a pure compound with any ratio of sodium to potassium (Na1-xKx)Cl by dissolving that ratio of NaCl and KCl in water and then evaporating the solution. A member of this family is sold under t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 times for its use as a pigment (brown ochre). Evidence has been found of its use in paint pigment samples taken from the caves of Lascaux in France. It was first described in 1806 based on samples found in the Hollertszug Mine in Herdorf, Germany. The mineral was named after the German polymath and poet Johann Wolfgang von Goethe (1749–1832). Composition Goethite is an iron oxyhydroxide containing ferric iron. It is the main component of rust and bog iron ore. Goethite's hardness ranges from 5.0 to 5.5 on the Mohs Scale, and its specific gravity varies from 3.3 to 4.3. The mineral forms prismatic needle-like crystals ("needle ironstone") but is more typically massive. Feroxyhyte and lepidocrocite are both polymorphs of the iron oxy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 hardness of 3.5 to 4 on the Mohs scale. Its streak is diagnostic as green-tinged black. On exposure to air, chalcopyrite tarnishes to a variety of oxides, hydroxides, and sulfates. Associated copper minerals include the sulfides bornite (Cu5FeS4), chalcocite (Cu2S), covellite (CuS), digenite (Cu9S5); carbonates such as malachite and azurite, and rarely oxides such as cuprite (Cu2O). Is rarely found in association with native copper. Chalcopyrite is a conductor of electricity. Etymology The name chalcopyrite comes from the Greek words , which means copper, and ', which means striking fire. It was sometimes historically referred to as "yellow copper". Identification Chalcopyrite is often confused with pyrite and gold since all three of these minerals have a yell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
