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Purpurin (glass)
Purpurin (Italian: ''Porporino''; Latin: ''Haematinum'', derived from Greek ''haimátinos'' = "of blood"; German: ''Hämatinon''), sometimes referred to as ''glass porphyr'', is an opaque glass of brownish to lustrous deep-reddish color which in classical antiquity was used for residential luxury objects, mosaics and various decorative purposes. Purpurin is somewhat harder than normal glass but can be easily cut and polished. Its red color is permanently lost upon smelting. The material bears some resemblance to goldstone. Historical references and archeology Purpurin artifacts are frequently found during archeological excavations of more affluent Roman settlements, often along with actual Roman glass; Pompeii is a prime example. Pliny the Elder reports in his '' Historia naturalis'': "Obsidian is made by artificial coloring and used for dishware, and also a completely red and opaque glass called haematinum." The art of making this type of glass seems to have originated in Indi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Classical Antiquity
Classical antiquity (also the classical era, classical period or classical age) is the period of cultural history between the 8th century BC and the 5th century AD centred on the Mediterranean Sea, comprising the interlocking civilizations of ancient Greece and ancient Rome known as the Greco-Roman world. It is the period in which both Greek and Roman societies flourished and wielded huge influence throughout much of Europe, North Africa, and Western Asia. Conventionally, it is taken to begin with the earliest-recorded Epic Greek poetry of Homer (8th–7th-century BC), and continues through the emergence of Christianity (1st century AD) and the fall of the Western Roman Empire (5th-century AD). It ends with the decline of classical culture during late antiquity (250–750), a period overlapping with the Early Middle Ages (600–1000). Such a wide span of history and territory covers many disparate cultures and periods. ''Classical antiquity'' may also refer to an idealized v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Max Joseph Von Pettenkofer
Max Joseph Pettenkofer, ennobled in 1883 as Max Joseph von Pettenkofer (3 December 1818 – 10 February 1901) was a Bavarian chemist and hygienist. He is known for his work in practical hygiene, as an apostle of good water, fresh air and proper sewage disposal. He was further known as an anti-contagionist, a school of thought, named later on, that did not believe in the then novel concept that bacteria were the main cause of disease. In particular he argued in favor of a variety of conditions collectively contributing to the incidence of disease including: personal state of health, the fermentation of environmental ground water, and also the germ in question. He was most well known for his establishment of hygiene as an experimental science and also was a strong proponent for the founding of hygiene institutes in Germany. His work served as an example which other institutes around the world emulated. Early life and education Pettenkofer was born in Lichtenheim, near Neuburg an der ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stained Glass
Stained glass is coloured glass as a material or works created from it. Throughout its thousand-year history, the term has been applied almost exclusively to the windows of churches and other significant religious buildings. Although traditionally made in flat panels and used as windows, the creations of modern stained glass artists also include three-dimensional structures and sculpture. Modern vernacular usage has often extended the term "stained glass" to include domestic lead light and ''objets d'art'' created from foil glasswork exemplified in the famous lamps of Louis Comfort Tiffany. As a material ''stained glass'' is glass that has been coloured by adding metallic salts during its manufacture, and usually then further decorating it in various ways. The coloured glass is crafted into ''stained glass windows'' in which small pieces of glass are arranged to form patterns or pictures, held together (traditionally) by strips of lead and supported by a rigid frame. Painte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quartz
Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of SiO2. Quartz is the second most abundant mineral in Earth's continental crust, behind feldspar. Quartz exists in two forms, the normal α-quartz and the high-temperature β-quartz, both of which are chiral. The transformation from α-quartz to β-quartz takes place abruptly at . Since the transformation is accompanied by a significant change in volume, it can easily induce microfracturing of ceramics or rocks passing through this temperature threshold. There are many different varieties of quartz, several of which are classified as gemstones. Since antiquity, varieties of quartz have been the most commonly used minerals in the making of jewelry and hardstone carvings, especially in Eurasia. Quartz is the mineral defining the val ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Borax
Borax is a salt (ionic compound), a hydrated borate of sodium, with chemical formula often written . It is a colorless crystalline solid, that dissolves in water to make a basic solution. It is commonly available in powder or granular form, and has many industrial and household uses, including as a pesticide, as a metal soldering flux, as a component of glass, enamel, and pottery glazes, for tanning of skins and hides, for artificial aging of wood, as a preservative against wood fungus, and as a pharmaceutic alkalizer. In chemical laboratories, it is used as a buffering agent. The compound is often called sodium tetraborate decahydrate, but that name is not consistent with its structure. The anion is not tetraborate but tetrahydroxy tetraborate , so the more correct formula should be . Informally, the product is often called sodium borate decahydrate or just sodium borate. The terms tincal "tinkle" and tincar "tinker" refer to native borax, historically mined from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lead
Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cut, lead is a shiny gray with a hint of blue. It tarnishes to a dull gray color when exposed to air. Lead has the highest atomic number of any stable element and three of its isotopes are endpoints of major nuclear decay chains of heavier elements. Lead is toxic, even in small amounts, especially to children. Lead is a relatively unreactive post-transition metal. Its weak metallic character is illustrated by its amphoteric nature; lead and lead oxides react with acids and bases, and it tends to form covalent bonds. Compounds of lead are usually found in the +2 oxidation state rather than the +4 state common with lighter members of the carbon group. Exceptions are mostly limited to organolead compounds. Like the lighter members of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emanuel Kayser
Friedrich Heinrich Emanuel Kayser (March 26, 1845November 29, 1927) was a German geologist and palaeontologist, born in Königsberg. He was educated at the universities of Halle, Heidelberg and Berlin, where in 1871 he qualified as a lecturer in geology. From 1873 he worked as a state geologist for the ''Preußischen Geologischen Landesanstalt'' (Prussian Geological Survey), and in 1881 became a professor at the Berlin Mining Academy. In 1885 he succeeded Wilhelm Dunker as professor of geology and paleontology at the University of Marburg.Kayser Meyers Großes Konversations-Lexikon, Band 10. Leipzig 1907, S. 795-796. In: |
Magnesium Oxide
Magnesium oxide ( Mg O), or magnesia, is a white hygroscopic solid mineral that occurs naturally as periclase and is a source of magnesium (see also oxide). It has an empirical formula of MgO and consists of a lattice of Mg2+ ions and O2− ions held together by ionic bonding. Magnesium hydroxide forms in the presence of water (MgO + H2O → Mg(OH)2), but it can be reversed by heating it to remove moisture. Magnesium oxide was historically known as magnesia alba (literally, the white mineral from Magnesia), to differentiate it from ''magnesia negra'', a black mineral containing what is now known as manganese. Related oxides While "magnesium oxide" normally refers to MgO, the compound magnesium peroxide MgO2 is also known. According to evolutionary crystal structure prediction, MgO2 is thermodynamically stable at pressures above 116 GPa (gigapascals), and a semiconducting suboxide Mg3O2 is thermodynamically stable above 500 GPa. Because of its stability, MgO is used as a model sy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetite
Magnetite is a mineral and one of the main iron ores, with the chemical formula Fe2+Fe3+2O4. It is one of the oxides of iron, and is ferrimagnetic; it is attracted to a magnet and can be magnetized to become a permanent magnet itself. With the exception of extremely rare native iron deposits, it is the most magnetic of all the naturally occurring minerals on Earth. Naturally magnetized pieces of magnetite, called lodestone, will attract small pieces of iron, which is how ancient peoples first discovered the property of magnetism. Magnetite is black or brownish-black with a metallic luster, has a Mohs hardness of 5–6 and leaves a black streak. Small grains of magnetite are very common in igneous and metamorphic rocks. The chemical IUPAC name is iron(II,III) oxide and the common chemical name is ''ferrous-ferric oxide''. Properties In addition to igneous rocks, magnetite also occurs in sedimentary rocks, including banded iron formations and in lake and marine sediments ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copper(II) Oxide
Copper(II) oxide or cupric oxide is an inorganic compound with the formula CuO. A black solid, it is one of the two stable oxides of copper, the other being Cu2O or copper(I) oxide (cuprous oxide). As a mineral, it is known as tenorite. It is a product of copper mining and the precursor to many other copper-containing products and chemical compounds. Production It is produced on a large scale by pyrometallurgy, as one stage in extracting copper from its ores. The ores are treated with an aqueous mixture of ammonium carbonate, ammonia, and oxygen to give copper(I) and copper(II) ammine complexes, which are extracted from the solids. These complexes are decomposed with steam to give CuO. It can be formed by heating copper in air at around 300–800°C: : 2 Cu + O2 → 2 CuO For laboratory uses, pure copper(II) oxide is better prepared by heating copper(II) nitrate, copper(II) hydroxide, or basic copper(II) carbonate: : 2 Cu(NO3)2(s) → 2 CuO(s) + 4 NO2(g) + O2(g) (180° ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ludwig I Of Bavaria
en, Louis Charles Augustus , image = Joseph Karl Stieler - King Ludwig I in his Coronation Robes - WGA21796.jpg , caption = Portrait by Joseph Stieler, 1825 , succession=King of Bavaria , reign = , coronation = , predecessor = Maximilian I Joseph , successor = Maximilian II , birth_name = , birth_date = , birth_place =Strasbourg, Kingdom of France , death_date = , death_place =Nice, Second French Empire , spouse =Therese of Saxe-Hildburghausen , issue =Maximilian II of Bavaria Mathilde Caroline, Grand Duchess of Hesse and by RhineOtto of GreecePrincess TheodelindeLuitpold, Prince Regent of Bavaria Adelgunde, Duchess of Modena Archduchess Hildegard of Austria Princess Alexandra Prince Adalbert , house =Wittelsbach , father =Maximilian I Joseph of Bavaria , mother =Princess Augusta Wilhelmine of Hesse-Darmstadt , religion =Roman Catholicism , burial_place ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mosaics
A mosaic is a pattern or image made of small regular or irregular pieces of colored stone, glass or ceramic, held in place by plaster/mortar, and covering a surface. Mosaics are often used as floor and wall decoration, and were particularly popular in the Ancient Roman world. Mosaic today includes not just murals and pavements, but also artwork, hobby crafts, and industrial and construction forms. Mosaics have a long history, starting in Mesopotamia in the 3rd millennium BC. Pebble mosaics were made in Tiryns in Mycenean Greece; mosaics with patterns and pictures became widespread in classical times, both in Ancient Greece and Ancient Rome. Early Christian basilicas from the 4th century onwards were decorated with wall and ceiling mosaics. Mosaic art flourished in the Byzantine Empire from the 6th to the 15th centuries; that tradition was adopted by the Norman Kingdom of Sicily in the 12th century, by the eastern-influenced Republic of Venice, and among the Rus. Mosaic fell ou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
