|
Rosenbergite
Rosenbergite is a mineral with the chemical formula Al F3·3 H2O. It is a trihydrate of aluminium fluoride. It is colorless. Its crystals are tetragonal to dipyramidal. It is named after Philip E. Rosenberg, a United States geochemist. It is found in the Celtine Mine in Tuscany, Italy and Mount Erebus, Ross Island, Antarctica. It is not radioactive. Rosenbergite is rated 3–3.5 on the Mohs Scale The Mohs scale of mineral hardness () is a qualitative ordinal scale, from 1 to 10, characterizing scratch resistance of various minerals through the ability of harder material to scratch softer material. The scale was introduced in 1812 by .... References External linksWebmineral - Rosenbergite [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aluminium Fluoride
Aluminium fluoride refers to inorganic compounds with the formula AlF3·''x''H2O. They are all colorless solids. Anhydrous AlF3 is used in the production of aluminium metal. Several occur as minerals. Occurrence and production Aside from anhydrous AlF3, several hydrates are known. With the formula AlF3·''x''H2O, these compounds include monohydrate (''x'' = 1), two polymorphs of the trihydrate (''x'' = 3), a hexahydrate (''x'' = 6), and a nonahydrate (''x'' = 9). The majority of aluminium fluoride is produced by treating alumina with hydrogen fluoride at 700 °C: Hexafluorosilicic acid may also be used make aluminum fluoride. :H2SiF6 + Al2O3 + 3 H2O → 2 AlF3 + SiO2 + 4 H2O Alternatively, it is manufactured by thermal decomposition of ammonium hexafluoroaluminate. For small scale laboratory preparations, AlF3 can also be prepared by treating aluminium hydroxide or aluminium metal with hydrogen fluoride. Aluminium fluoride trihydrate is found in nature as the rare mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siena
Siena ( , ; lat, Sena Iulia) is a city in Tuscany, Italy. It is the capital of the province of Siena. The city is historically linked to commercial and banking activities, having been a major banking center until the 13th and 14th centuries. Siena is also home to the oldest bank in the world, the Monte dei Paschi bank, which has been operating continuously since 1472. Several significant Renaissance painters worked and were born in Siena, among them Duccio, Ambrogio Lorenzetti, Simone Martini and Sassetta, and influenced the course of Italian and European art. The University of Siena, originally called ''Studium Senese'', was founded in 1240, making it one of the oldest universities in continuous operation in the world. Siena was one of the most important cities in medieval Europe, and its historic centre is a UNESCO World Heritage Site. From January until the end of September of 2021 it had about 217,000 arrivals, with the largest numbers of foreign visitors coming ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuscany, Italy
Tuscany ( ; it, Toscana ) is a Regions of Italy, region in central Italy with an area of about and a population of about 3.8 million inhabitants. The regional capital is Florence (''Firenze''). Tuscany is known for its landscapes, history, artistic legacy, and its influence on high culture. It is regarded as the birthplace of the Italian Renaissance and of the foundations of the Italian language. The prestige established by the Tuscan dialect's use in literature by Dante Alighieri, Petrarch, Giovanni Boccaccio, Niccolò Machiavelli and Francesco Guicciardini led to its subsequent elaboration as the language of culture throughout Italy. It has been home to many figures influential in the history of art and science, and contains well-known museums such as the Uffizi and the Palazzo Pitti. Tuscany is also known for its wines, including Chianti, Vino Nobile di Montepulciano, Morellino di Scansano, Brunello di Montalcino and white Vernaccia di San Gimignano. Having a strong linguisti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluorine Minerals
Fluorine is a chemical element with the symbol F and atomic number 9. It is the lightest halogen and exists at standard conditions as a highly toxic, pale yellow diatomic gas. As the most electronegative reactive element, it is extremely reactive, as it reacts with all other elements except for the light inert gases. Among the elements, fluorine ranks 24th in universal abundance and 13th in terrestrial abundance. Fluorite, the primary mineral source of fluorine which gave the element its name, was first described in 1529; as it was added to metal ores to lower their melting points for smelting, the Latin verb meaning 'flow' gave the mineral its name. Proposed as an element in 1810, fluorine proved difficult and dangerous to separate from its compounds, and several early experimenters died or sustained injuries from their attempts. Only in 1886 did French chemist Henri Moissan isolate elemental fluorine using low-temperature electrolysis, a process still employed for modern produc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aluminium Minerals
Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It has a great affinity towards oxygen, and forms a protective layer of oxide on the surface when exposed to air. Aluminium visually resembles silver, both in its color and in its great ability to reflect light. It is soft, non-magnetic and ductile. It has one stable isotope, 27Al; this isotope is very common, making aluminium the twelfth most common element in the Universe. The radioactivity of 26Al is used in radiodating. Chemically, aluminium is a post-transition metal in the boron group; as is common for the group, aluminium forms compounds primarily in the +3 oxidation state. The aluminium cation Al3+ is small and highly charged; as such, it is polarizing, and bonds aluminium forms tend towards covalency. The strong affinity towards oxyg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mohs Scale
The Mohs scale of mineral hardness () is a qualitative ordinal scale, from 1 to 10, characterizing scratch resistance of various minerals through the ability of harder material to scratch softer material. The scale was introduced in 1812 by the German geologist and mineralogist Friedrich Mohs, in his book ''"Versuch einer Elementar-Methode zur naturhistorischen Bestimmung und Erkennung der Fossilien"''; it is one of several definitions of hardness in materials science, some of which are more quantitative. The method of comparing hardness by observing which minerals can scratch others is of great antiquity, having been mentioned by Theophrastus in his treatise ''On Stones'', , followed by Pliny the Elder in his ''Naturalis Historia'', . The Mohs scale is useful for identification of minerals in the field, but is not an accurate predictor of how well materials endure in an industrial setting – ''toughness''. Minerals The Mohs scale of mineral hardness is based on the ability ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radioactive
Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is considered radioactive. Three of the most common types of decay are alpha decay ( ), beta decay ( ), and gamma decay ( ), all of which involve emitting one or more particles. The weak force is the mechanism that is responsible for beta decay, while the other two are governed by the electromagnetism and nuclear force. A fourth type of common decay is electron capture, in which an unstable nucleus captures an inner electron from one of the electron shells. The loss of that electron from the shell results in a cascade of electrons dropping down to that lower shell resulting in emission of discrete X-rays from the transitions. A common example is iodine-125 commonly used in medical settings. Radioactive decay is a stochastic (i.e. random) process ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antarctica
Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest continent, being about 40% larger than Europe, and has an area of . Most of Antarctica is covered by the Antarctic ice sheet, with an average thickness of . Antarctica is, on average, the coldest, driest, and windiest of the continents, and it has the highest average elevation. It is mainly a polar desert, with annual precipitation of over along the coast and far less inland. About 70% of the world's freshwater reserves are frozen in Antarctica, which, if melted, would raise global sea levels by almost . Antarctica holds the record for the lowest measured temperature on Earth, . The coastal regions can reach temperatures over in summer. Native species of animals include mites, nematodes, penguins, seals and tardigrades. Where vegetation o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ross Island
Ross Island is an island formed by four volcanoes in the Ross Sea near the continent of Antarctica, off the coast of Victoria Land in McMurdo Sound. Ross Island lies within the boundaries of Ross Dependency, an area of Antarctica claimed by New Zealand. History Discovery Sir James Ross discovered it in 1840, and it was later named in honour of him by Robert F. Scott. Ross Island was the base for many of the early expeditions to Antarctica. It is the southernmost island reachable by sea. Huts built by Scott's and Shackleton's expeditions are still standing on the island, preserved as historical sites. Today Ross Island is home to New Zealand's Scott Base, and the largest Antarctic settlement, the U.S. Antarctic Program's McMurdo Station. Greenpeace established World Park Base on the island and ran it for five years, from 1987 to 1992. Geography Because of the persistent presence of the ice sheet, the island is sometimes taken to be part of the Antarctic mainland. Its are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mount Erebus
Mount Erebus () is the second-highest volcano in Antarctica (after Mount Sidley), the highest active volcano in Antarctica, and the southernmost active volcano on Earth. It is the sixth-highest ultra mountain on the continent. With a summit elevation of , it is located in the Ross Dependency on Ross Island, which is also home to three inactive volcanoes: Mount Terror, Mount Bird, and Mount Terra Nova. The volcano has been active since about 1.3 million years ago and has a long-lived lava lake in its inner summit crater that has been present since at least the early 1970s. The volcano was the site of the Air New Zealand Flight 901 accident, which occurred in November 1979. Geology and volcanology Mount Erebus is the world's southernmost active volcano. It is the current eruptive centre of the Erebus hotspot. The summit contains a persistent convecting phonolitic lava lake, one of five long-lasting lava lakes on Earth. Characteristic eruptive activity consists of Str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Celtine Mine
In Greek mythology, Celtine ( grc, Κελτίνη, ''Keltine'') was the daughter of Bretannus and mother of Celtus. She is known for having been one of the consorts of Heracles. Mythology Her story, recorded by Parthenius of Nicaea, is as follows. When Heracles was driving the cattle of Geryon to Greece, he stopped at Bretannus' house. Celtine fell in love with her father's guest and tricked him into consorting with her: she hid away the kine and told Heracles that in order to get the herd back, he had to make love to her. Heracles, both anxious to bring the cattle safe to Eurystheus and overcome by Celtine's beauty, consented. From their union was born a son Celtus, eponym of the Celts. Parthenius, ''Love Romances'', 30. Transl. by S. Gaselee (1916at Classical E-text/ref> A version of this myth is also found in the ''Etymologicum Magnum''. It refers to the heroine as Celto (Κελτώ, ''Kelto''), and tells that Heracles left her his bow, telling her that their future child – ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aluminum
Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It has a great affinity towards oxygen, and forms a protective layer of oxide on the surface when exposed to air. Aluminium visually resembles silver, both in its color and in its great ability to reflect light. It is soft, non-magnetic and ductile. It has one stable isotope, 27Al; this isotope is very common, making aluminium the twelfth most common element in the Universe. The radioactivity of 26Al is used in radiodating. Chemically, aluminium is a post-transition metal in the boron group; as is common for the group, aluminium forms compounds primarily in the +3 oxidation state. The aluminium cation Al3+ is small and highly charged; as such, it is polarizing, and bonds aluminium forms tend towards covalency. The strong affinity towards ox ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
