Bohemia is the westernmost and largest historical region of the Czech lands in the present-day Czech Republic. In a broader meaning, Bohemia sometimes refers to the entire Czech territory, including Moravia and Czech Silesia in a historical context, such as the Lands of the Bohemian Crown ruled by Bohemian kings. Bohemia was a duchy of Great Moravia an independent principality, a kingdom in the Holy Roman Empire, subsequently a part of the Habsburg Monarchy and the Austrian Empire. After World War I and the establishment of an independent Czechoslovak state, Bohemia became a part of Czechoslovakia. Between 1938 and 1945, border regions with sizeable German-speaking minorities of all three Czech lands were joined to Nazi Germany as the Sudetenland; the remainder of Czech territory became the Second Czechoslovak Republic and was subsequently occupied as the Protectorate of Bohemia and Moravia, In 1969, the Czech lands were given autonomy within Czechoslovakia as the Czech Socialist Republic. In 1990, the name was changed to the Czech Republic, which became a separate state in 1993 with the split of Czechoslovakia.
Until 1948, Bohemia was an administrative unit of Czechoslovakia as one of its "lands". Since administrative reforms have replaced self-governing lands with a modified system of "regions" which do not follow the borders of the historical Czech lands. However, the three lands are mentioned in the preamble of the Constitution of the Czech Republic: "We, citizens of the Czech Republic in Bohemia and Silesia…"Bohemia had an area of 52,065 km2 and today is home to 6.5 million of the Czech Republic's 10.5 million inhabitants. Bohemia was bordered in the south by Upper and Lower Austria, in the west by Bavaria and in the north by Saxony and Lusatia, in the northeast by Silesia, in the east by Moravia. Bohemia's borders were marked by mountain ranges such as the Bohemian Forest, the Ore Mountains, the Krkonoše, a part of the Sudetes range. In the 2nd century BC, the Romans were competing for dominance in northern Italy with various peoples including the Gauls-Celtic tribe Boii; the Romans defeated the Boii at the Battle of Mutina.
After this, many of the Boii retreated north across the Alps. Much Roman authors refer to the area they had once occupied as Boiohaemum; the earliest mention was by Tacitus' Germania 28, mentions of the same name are in Strabo and Velleius Paterculus. The name appears to include the tribal name Boi- plus the Germanic element *haimaz "home"; this Boiohaemum was isolated to the area where King Marobod's kingdom was centred, within the Hercynian forest. Emperor Constantine VII in 10th century De Administrando Imperio mentioned the region as Boïki; the Czech name "Čechy" is derived from the name of the Slavic ethnic group, the Czechs, who settled in the area during the 6th or 7th century AD. Bohemia, like neighbouring Bavaria, is named after the Boii, who were a large Celtic nation known to the Romans for their migrations and settlement in northern Italy and other places. Another part of the nation moved west with the Helvetii into southern France, one of the events leading to the interventions of Julius Caesar's Gaulish campaign of 58 BC.
The emigration of the Helvetii and Boii left southern Germany and Bohemia a inhabited "desert" into which Suebic peoples arrived, speaking Germanic languages, became dominant over remaining Celtic groups. To the south, over the Danube, the Romans extended their empire, to the southeast in present-day Hungary, were Dacian peoples. In the area of modern Bohemia the Marcomanni and other Suebic groups were led by their king Marobodus, after suffering defeat to Roman forces in Germany, he took advantage of the natural defenses provided by its forests. They were able to maintain a strong alliance with neighbouring tribes including the Lugii, Hermunduri and Buri, sometimes controlled by the Roman Empire, sometimes in conflict with it, for example in the second century when they fought Marcus Aurelius. In late classical times and the early Middle Ages, two new Suebic groupings appeared to the west of Bohemia in southern Germany, the Alemanni, the Bavarians. Many Suebic tribes from the Bohemian region took part in such movements westwards settling as far away as Spain and Portugal.
With them were tribes who had pushed from the east, such as the Vandals, Alans. Other groups pushed southwards towards Pannonia; the last known mention of the kingdom of the Marcomanni, concerning a queen named Fritigil is in the 4th century, she was thought to have lived in or near Pannonia. The Suebian Langobardi, who moved over many generations from the Baltic Sea, via the Elbe and Pannonia to Italy, recorded in a tribal history a time spent in "Bainaib". After this migration period, Bohemia was repopulated around the 6th century, Slavic tribes arrived from the east, their language began to replace the older Germanic and Sarmatian ones; these are precursors of today's Czechs, though the exact amount of Slavic immigration is a subject of debate. The Slavic influx was divided into three waves; the first wave came from the
Arsenopyrite is an iron arsenic sulfide. It is a hard metallic, steel grey to silver white mineral with a high specific gravity of 6.1. When dissolved in nitric acid, it releases elemental sulfur; when arsenopyrite is heated, it produces poisonous sulfur and arsenic fumes which can be fatal if inhaled in large quantities. With 46% arsenic content, along with orpiment, is a principal ore of arsenic; when deposits of arsenopyrite become exposed to the atmosphere, the mineral will oxidize, converting the arsenopyrite into an iron arsenate, a stable compound. Arsenopyrite is an acid consuming sulfide mineral unlike iron pyrite which can lead to acid mine drainage; the crystal habit, hardness and garlic odor when struck are diagnostic. Arsenopyrite in older literature may be referred to a name of German origin. Arsenopyrite can be associated with significant amounts of gold, it serves as an indicator of gold bearing reefs. Many arsenopyrite gold ores are refractory, i.e. the gold is not cyanide leached from the mineral matrix.
Arsenopyrite is found in high temperature hydrothermal veins, in pegmatites, in areas of contact metamorphism or metasomatism. Arsenopyrite crystallizes in the monoclinic crystal system and shows prismatic crystal or columnar forms with striations and twinning common. Arsenopyrite may be referred to in older references as orthorhombic, but it has been shown to be monoclinic. In terms of its atomic structure, each Fe center is linked to three As three S atoms; the material can be described as Fe3+ with the diatomic trianion AsS3−. The connectivity of the atoms is more similar to that in marcasite than pyrite; the ion description is imperfect because the material is semiconducting and the Fe-As and Fe-S bonds are covalent. Various transition group metals can substitute for iron in arsenopyrite; the arsenopyrite group includes the following rare minerals: Clinosafflorite: AsS Gudmundite: FeSbS Glaucodot or alloclasite: AsS or AsS Iridarsenite: AsS Osarsite or ruarsite: AsS or AsS Classification of minerals List of minerals
The mineral pyrite, or iron pyrite known as fool's gold, is an iron sulfide with the chemical formula FeS2. Pyrite is considered the most common of the sulfide minerals. Pyrite's metallic luster and pale brass-yellow hue give it a superficial resemblance to gold, hence the well-known nickname of fool's gold; the color has led to the nicknames brass and Brazil used to refer to pyrite found in coal. The name pyrite is derived from the Greek πυρίτης, "of fire" or "in fire", in turn from πύρ, "fire". In ancient Roman times, this name was applied to several types of stone that would create sparks when struck against steel. By Georgius Agricola's time, c. 1550, the term had become a generic term for all of the sulfide minerals. Pyrite is found associated with other sulfides or oxides in quartz veins, sedimentary rock, metamorphic rock, as well as in coal beds and as a replacement mineral in fossils, but has been identified in the sclerites of scaly-foot gastropods. Despite being nicknamed fool's gold, pyrite is sometimes found in association with small quantities of gold.
Gold and arsenic occur as a coupled substitution in the pyrite structure. In the Carlin–type gold deposits, arsenian pyrite contains up to 0.37% gold by weight. Pyrite enjoyed brief popularity in the 16th and 17th centuries as a source of ignition in early firearms, most notably the wheellock, where a sample of pyrite was placed against a circular file to strike the sparks needed to fire the gun. Pyrite has been used since classical times to manufacture copperas. Iron pyrite was allowed to weather; the acidic runoff from the heap was boiled with iron to produce iron sulfate. In the 15th century, new methods of such leaching began to replace the burning of sulfur as a source of sulfuric acid. By the 19th century, it had become the dominant method. Pyrite remains in commercial use for the production of sulfur dioxide, for use in such applications as the paper industry, in the manufacture of sulfuric acid. Thermal decomposition of pyrite into FeS and elemental sulfur starts at 540 °C. A newer commercial use for pyrite is as the cathode material in Energizer brand non-rechargeable lithium batteries.
Pyrite is a semiconductor material with a band gap of 0.95 eV. Pure pyrite is n-type, in both crystal and thin-film forms due to sulfur vacancies in the pyrite crystal structure acting as n-dopants. During the early years of the 20th century, pyrite was used as a mineral detector in radio receivers, is still used by crystal radio hobbyists; until the vacuum tube matured, the crystal detector was the most sensitive and dependable detector available – with considerable variation between mineral types and individual samples within a particular type of mineral. Pyrite detectors occupied a midway point between galena detectors and the more mechanically complicated perikon mineral pairs. Pyrite detectors can be as sensitive as a modern 1N34A germanium diode detector. Pyrite has been proposed as an abundant, non-toxic, inexpensive material in low-cost photovoltaic solar panels. Synthetic iron sulfide was used with copper sulfide to create the photovoltaic material.. More recent efforts are working toward thin-film solar cells made of pyrite.
Pyrite is used to make marcasite jewelry. Marcasite jewelry, made from small faceted pieces of pyrite set in silver, was known since ancient times and was popular in the Victorian era. At the time when the term became common in jewelry making, "marcasite" referred to all iron sulfides including pyrite, not to the orthorhombic FeS2 mineral marcasite, lighter in color and chemically unstable, thus not suitable for jewelry making. Marcasite jewelry does not contain the mineral marcasite. China represents the main importing country with an import of around 376,000 tonnes, which resulted at 45% of total global imports. China is the fastest growing in terms of the unroasted iron pyrites imports, with a CAGR of +27.8% from 2007 to 2016. In value terms, China constitutes the largest market for imported unroasted iron pyrites worldwide, making up 65% of global imports. From the perspective of classical inorganic chemistry, which assigns formal oxidation states to each atom, pyrite is best described as Fe2+S22−.
This formalism recognizes. These persulfide units can be viewed as derived from hydrogen disulfide, H2S2, thus pyrite would be more descriptively, not iron disulfide. In contrast, molybdenite, MoS2, features isolated sulfide centers and the oxidation state of molybdenum is Mo4+; the mineral arsenopyrite has the formula FeAsS. Whereas pyrite has S2 subunits, arsenopyrite has units, formally derived from deprotonation of H2AsSH. Analysis of classical oxidation states would recommend the description of arsenopyrite as Fe3+3−. Iron-pyrite FeS2 represents the prototype compound of the crystallographic pyrite structure; the structure is simple cubic and was among the first crystal structures solved by X-ray diffraction. It belongs to the crystallographic space group Pa3 and is denoted by the Strukturbericht notation C2. Under thermodynamic standard conditions the lattice constant a of stoichiometric iron pyrite FeS2 amounts to 541.87 pm. The unit cell is composed of a Fe face-centered cubic sublattice into.
The pyrite structure is used by other compounds MX2 of trans
Monoclinic crystal system
In crystallography, the monoclinic crystal system is one of the 7 crystal systems. A crystal system is described by three vectors. In the monoclinic system, the crystal is described by vectors of unequal lengths, as in the orthorhombic system, they form a rectangular prism with a parallelogram as its base. Hence two vectors are perpendicular, while the third vector meets the other two at an angle other than 90°. There is only one monoclinic Bravais lattice in two dimensions: the oblique lattice. Two monoclinic Bravais lattices exist: the primitive monoclinic and the base-centered monoclinic lattices. In the monoclinic system there is a used second choice of crystal axes that results in a unit cell with the shape of an oblique rhombic prism. In this axis setting, the primitive and base-centered lattices swap in centering type; the table below organizes the space groups of the monoclinic crystal system by crystal class. It lists the International Tables for Crystallography space group numbers, followed by the crystal class name, its point group in Schoenflies notation, Hermann–Mauguin notation, orbifold notation, Coxeter notation, type descriptors, mineral examples, the notation for the space groups.
Sphenoidal is monoclinic hemimorphic. The three monoclinic hemimorphic space groups are as follows: a prism with as cross-section wallpaper group p2 ditto with screw axes instead of axes ditto with screw axes as well as axes, parallel, in between; the four monoclinic hemihedral space groups include those with pure reflection at the base of the prism and halfway those with glide planes instead of pure reflection planes. Crystal structure Crystallography Crystal Hurlbut, Cornelius S.. Manual of Mineralogy. Pp. 69–73. ISBN 0-471-80580-7. Hahn, Theo, ed.. International Tables for Crystallography, Volume A: Space Group Symmetry. A. Berlin, New York: Springer-Verlag. Doi:10.1107/97809553602060000100. ISBN 978-0-7923-6590-7
Transparency and translucency
In the field of optics, transparency is the physical property of allowing light to pass through the material without being scattered. On a macroscopic scale, the photons can be said to follow Snell's Law. Translucency is a superset of transparency: it allows light to pass through, but does not follow Snell's law. In other words, a translucent medium allows the transport of light while a transparent medium not only allows the transport of light but allows for image formation. Transparent materials appear clear, with the overall appearance of one color, or any combination leading up to a brilliant spectrum of every color; the opposite property of translucency is opacity. When light encounters a material, it can interact with it in several different ways; these interactions depend on the nature of the material. Photons interact with an object by some combination of reflection and transmission; some materials, such as plate glass and clean water, transmit much of the light that falls on them and reflect little of it.
Many liquids and aqueous solutions are transparent. Absence of structural defects and molecular structure of most liquids are responsible for excellent optical transmission. Materials which do not transmit light are called opaque. Many such substances have a chemical composition which includes what are referred to as absorption centers. Many substances are selective in their absorption of white light frequencies, they absorb certain portions of the visible spectrum while reflecting others. The frequencies of the spectrum which are not absorbed are either reflected or transmitted for our physical observation; this is. The attenuation of light of all frequencies and wavelengths is due to the combined mechanisms of absorption and scattering. Transparency can provide perfect camouflage for animals able to achieve it; this is easier in turbid seawater than in good illumination. Many marine animals such as jellyfish are transparent. With regard to the absorption of light, primary material considerations include: At the electronic level, absorption in the ultraviolet and visible portions of the spectrum depends on whether the electron orbitals are spaced such that they can absorb a quantum of light of a specific frequency, does not violate selection rules.
For example, in most glasses, electrons have no available energy levels above them in range of that associated with visible light, or if they do, they violate selection rules, meaning there is no appreciable absorption in pure glasses, making them ideal transparent materials for windows in buildings. At the atomic or molecular level, physical absorption in the infrared portion of the spectrum depends on the frequencies of atomic or molecular vibrations or chemical bonds, on selection rules. Nitrogen and oxygen are not greenhouse gases because there is no absorption, but because there is no molecular dipole moment. With regard to the scattering of light, the most critical factor is the length scale of any or all of these structural features relative to the wavelength of the light being scattered. Primary material considerations include: Crystalline structure: whether or not the atoms or molecules exhibit the'long-range order' evidenced in crystalline solids. Glassy structure: scattering centers include fluctuations in density or composition.
Microstructure: scattering centers include internal surfaces such as grain boundaries, crystallographic defects and microscopic pores. Organic materials: scattering centers include fiber and cell structures and boundaries. Diffuse reflection - Generally, when light strikes the surface of a solid material, it bounces off in all directions due to multiple reflections by the microscopic irregularities inside the material, by its surface, if it is rough. Diffuse reflection is characterized by omni-directional reflection angles. Most of the objects visible to the naked eye are identified via diffuse reflection. Another term used for this type of reflection is "light scattering". Light scattering from the surfaces of objects is our primary mechanism of physical observation. Light scattering in liquids and solids depends on the wavelength of the light being scattered. Limits to spatial scales of visibility therefore arise, depending on the frequency of the light wave and the physical dimension of the scattering center.
Visible light has a wavelength scale on the order of a half a micrometer. Scattering centers as small. Optical transparency in polycrystalline materials is limited by the amount of light, scattered by their microstructural features. Light scattering depends on the wavelength of the light. Limits to spatial scales of visibility therefore arise, depending on the frequency of the light wave and the physical dimension of the scattering center. For example, since visible light has a wavelength scale on the order of a micrometer, scattering centers will have dimensions on a similar spatial scale. Primary scattering centers in polycrystalline materi
Kutná Hora is a town in the Central Bohemian Region of the Czech Republic. The town began in 1142 with the settlement of Sedlec Abbey, the first Cistercian monastery in Bohemia, Sedlec Monastery, brought from the Imperial immediate Cistercian Waldsassen Abbey. By 1260, German miners began to mine for silver in the mountain region, which they named Kuttenberg, and, part of the monastery property; the name of the mountain is said to have derived from the word mining. Under Abbot Heidenreich, the territory advanced due to the silver mines which gained importance during the economic boom of the 13th century; the earliest traces of silver have been found dating back to the 10th century, when Bohemia had been in the crossroads of long-distance trade for many centuries. Silver dinars have been discovered belonging to the period between 982–995 in the settlement of Malín, now a part of Kutná Hora. From the 13th to 16th centuries, the city competed with Prague economically and politically. Since 1995, the city center has been a UNESCO World Heritage Site.
In 1300, King Wenceslaus II of Bohemia issued. This was a legal document that specified all administrative as well as technical terms and conditions necessary for the operation of mines; the city developed with great rapidity, at the outbreak of the Hussite Wars in 1419 was the second most important city in Bohemia, after Prague, having become the favourite residence of several Bohemian kings. It was here that, on January 18, 1409, Wenceslaus IV signed the famous Decree of Kutná Hora, by which the Czech university nation was given three votes in the elections to the faculty of Prague University as against one for the three other nations. In 1420, Emperor Sigismund made the city the base for his unsuccessful attack on the Taborites during the Hussite Wars, leading to the Battle of Kutná Hora. Kuttenberg was taken by Jan Žižka, after a temporary reconciliation of the warring parties was burned by the imperial troops in 1422, to prevent its falling again into the hands of the Taborites. Žižka nonetheless took the place, under Bohemian auspices it awoke to a new period of prosperity.
Along with the rest of Bohemia, Kuttenberg passed to the Habsburg Monarchy of Austria in 1526. In 1546, the richest mine was flooded. In the insurrection of Bohemia against Ferdinand I the city lost all its privileges. Repeated visitations of the plague and the horrors of the Thirty Years' War completed its ruin. Half-hearted attempts after the peace to repair the ruined mines failed; the mines were abandoned at the end of the 18th century. In this town, Prague groschen were minted between 1300–1547/48. Bohemia was a crownland of the Austrian Empire in 1806, in the Austrian monarchy after the compromise of 1867); until 1918, Kuttenberg was the capital of the district of the same name, one of the 94 Bezirkshauptmannschaften in Bohemia. Together with the rest of Bohemia, the town became part of the newly founded Czechoslovakia after World War I and the collapse of Austria-Hungary. Kutná Hora was incorporated into the Protectorate of Bohemia and Moravia by Nazi Germany in the period 1939–1945, but was restored to Czechoslovakia after World War II.
The town became part of the Czech Republic after the dissolution of Czechoslovakia. Jakob Jakobeus, Slovak writer Jan Erazim Vocel, archaeologist and cultural revivalist František Zelenka, graphic, stage set and costume designer Terry Guo, founder of Taiwanese company Foxconn - in 2002 he bought a Roztěž castle near Kutná Hora The centre of Kutná Hora and Sedlec Abbey with its famous ossuary are a UNESCO World Heritage Site. Among the most important buildings in the town are the Gothic, five-naved St. Barbara's Church, begun in 1388, the Italian Court a royal residence and mint, built at the end of the 13th century; the Gothic Stone Haus, which since 1902 has served as a museum, contains one of the richest archives in the country. The Gothic St. James's Church, with its 86-metre tower, is another prominent building. Sedlec is the site of the Gothic Cathedral of the famous Ossuary. Church of St. Barbara Church of Our Lady Sedlec Ossuary Church of St. James Church of St. John Nepomuk Church of Ursuline Convent Jesuit College Italian Court Marian column Kutná Hora is twinned with: Bamenda, Cameroon Bingen am Rhein, Germany Eger, Hungary Fidenza, Italy Jinan, China Kamianets-Podilskyi, Ukraine Kremnica, Slovakia Reims, France Ringsted, Denmark Stamford, United Kingdom Tarnowskie Góry, Poland Deer Park Žehušice – natural reserve with white deer, located 15 km to the east Municipal website Kutná Hora travel guide from Wikivoyage Photo Gallery of Kutná Hora and Travel Information