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Harmotome
Harmotome is a mineral, one of the rarer zeolites; a hydrated barium silicate with formula: ( Ba0.5, Ca0.5, Na, K)5 Al5, Si11 O32·12( H2O). It forms vitreous white well defined monoclinic crystals, often associated with calcite and other zeolites. It has a Mohs hardness of 4 to 5 and a specific gravity of 2.44 to 2.5. Name and discovery Named from the Greek words grc, ἁρμός, harmos (a joint) and grc, τέμνειν, témnein (to cut) by René Just Haüy in 1801 because the pyramid divides parallel to the plane that passes through the terminal edges. It was first described in 1801 from an occurrence in the Harz Mountains, Lower Saxony, Germany. Location Like other zeolites, harmotome occurs with calcite in the amygdaloidal cavities of volcanic rocks, for example, in the dolerites of Dumbartonshire, and as fine crystals in the agate-lined cavities in the melaphyre of Oberstein in Germany. It also occurs in gneiss, and sometimes in metalliferous veins. At Sankt Andreasberg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brewsterite
Brewsterite is the name of a series of tectosilicate minerals of the zeolite group. Prior to 1997, brewsterite was recognized as a mineral species, but a reclassification in 1997 by the International Mineralogical Association changed it to a series name, with the mineral species being named brewsterite-Sr and brewsterite-Ba. Brewsterite-Sr, the more common of these, is a hydrous strontium and aluminium silicate, . Small amounts of barium is usually present replacing part of the strontium. The appropriate species name depends on the dominant element. The species are visually indistinguishable, and the series name brewsterite is still used whenever testing has not been performed. It is generally considered to be monoclinic, though optical studies have suggested it might be triclinic. It has one plane of perfect cleavage. The color is white, yellow-white, or gray. The Mohs' hardness is 5. It is transparent to translucent. The crystals are prismatic. Brewsterite is isomorphou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zeolites
Zeolites are microporous, crystalline aluminosilicate materials commonly used as commercial adsorbents and catalysts. They mainly consist of silicon, aluminium, oxygen, and have the general formula ･y where is either a metal ion or H+. These positive ions can be exchanged for others in a contacting electrolyte solution. exchanged zeolites are particularly useful as solid acid catalysts. The term ''zeolite'' was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt, who observed that rapidly heating a material, believed to have been stilbite, produced large amounts of steam from water that had been adsorbed by the material. Based on this, he called the material ''zeolite'', from the Greek , meaning "to boil" and , meaning "stone". Zeolites occur naturally but are also produced industrially on a large scale. , 253 unique zeolite frameworks have been identified, and over 40 naturally occurring zeolite frameworks are known. Every new zeolite structure that is obt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harz Mountains
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] |
Sodium Minerals
Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable isotope is 23Na. The free metal does not occur in nature, and must be prepared from compounds. Sodium is the sixth most abundant element in the Earth's crust and exists in numerous minerals such as feldspars, sodalite, and halite (NaCl). Many salts of sodium are highly water-soluble: sodium ions have been leached by the action of water from the Earth's minerals over eons, and thus sodium and chlorine are the most common dissolved elements by weight in the oceans. Sodium was first isolated by Humphry Davy in 1807 by the electrolysis of sodium hydroxide. Among many other useful sodium compounds, sodium hydroxide (lye) is used in soap manufacture, and sodium chloride (edible salt) is a de-icing agent and a nutrient for animals including human ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcium Minerals
Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to its heavier homologues strontium and barium. It is the fifth most abundant element in Earth's crust, and the third most abundant metal, after iron and aluminium. The most common calcium compound on Earth is calcium carbonate, found in limestone and the fossilised remnants of early sea life; gypsum, anhydrite, fluorite, and apatite are also sources of calcium. The name derives from Latin ''calx'' "lime", which was obtained from heating limestone. Some calcium compounds were known to the ancients, though their chemistry was unknown until the seventeenth century. Pure calcium was isolated in 1808 via electrolysis of its oxide by Humphry Davy, who named the element. Calcium compounds are widely used in many industries: in foods and pharmace ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barium Minerals
Barium is a chemical element with the symbol Ba and atomic number 56. It is the fifth element in group 2 and is a soft, silvery alkaline earth metal. Because of its high chemical reactivity, barium is never found in nature as a free element. The most common minerals of barium are baryte (barium sulfate, BaSO4) and witherite (barium carbonate, BaCO3). The name ''barium'' originates from the alchemical derivative "baryta", from Greek (), meaning 'heavy'. ''Baric'' is the adjectival form of barium. Barium was identified as a new element in 1774, but not reduced to a metal until 1808 with the advent of electrolysis. Barium has few industrial applications. Historically, it was used as a getter for vacuum tubes and in oxide form as the emissive coating on indirectly heated cathodes. It is a component of YBCO (high-temperature superconductors) and electroceramics, and is added to steel and cast iron to reduce the size of carbon grains within the microstructure. Barium compounds are ad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Argyll
Argyll (; archaically Argyle, in modern Gaelic, ), sometimes called Argyllshire, is a historic county and registration county of western Scotland. Argyll is of ancient origin, and corresponds to most of the part of the ancient kingdom of on Great Britain. Argyll was also a medieval bishopric with its cathedral at Lismore, as well as an early modern earldom and dukedom, the Dukedom of Argyll. It borders Inverness-shire to the north, Perthshire and Dunbartonshire to the east, and—separated by the Firth of Clyde—neighbours Renfrewshire and Ayrshire to the south-east, and Buteshire to the south. Between 1890 and 1975, Argyll was an administrative county with a county council. Its area corresponds with most of the modern council area of Argyll and Bute, excluding the Isle of Bute and the Helensburgh area, but including the Morvern and Ardnamurchan areas of the Highland council area. There was an Argyllshire constituency of the Parliament of Great Britain then Parli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strontian
Strontian (; gd, Sròn an t-Sìthein) is the main village in Sunart, an area in western Lochaber, Highland, Scotland, on the A861 road. Prior to 1975 it was part of Argyllshire. It lies on the north shore of Loch Sunart, close to the head of the loch. In the hills to the north of Strontian lead was mined in the 18th century and in these mines the mineral strontianite was discovered, from which the element strontium was first isolated. The village name in Gaelic, ''Sròn an t-Sìthein'', translates as the ''nose'' .e. 'point'''of the fairy hill'', meaning a knoll or low round hill inhabited by the mythological '' sídhe''. The nearby hamlets of Anaheilt, Bellsgrove, and Upper and Lower Scotstown are now generally considered part of Strontian, with Polloch several miles away on the terminus of the road to Loch Shiel. Strontian is the location of Ardnamurchan High School, the local fire station, police station and other facilities. Geology and mining history It was observed ... [...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] |
Sankt Andreasberg
Sankt Andreasberg is a former town in the Goslar (district), district of Goslar, in Lower Saxony, Germany. Since 1 November 2011, it is part of the town Braunlage. It is situated in the Harz, approximately 7 km west of Braunlage proper, and 20 km east of Osterode am Harz. History Sankt Andreasberg was founded in the 1480s. It was first mentioned in a letter from the Count Heinrich zu Stolberg to Dietrich von Witzlebenon on 3 November 1487. The establishment of the village took place around the market. The first silver mines are assumed to be the St. Andrews Cross Mine (german: Grube St. Andreaskreuz) at the foot of the ''Beerberg'' and the St. Andrews Mine (''Grube St. Andreas'') by the market. In 1521, St. Andreasberg received the right to mine from Counts Heinrich and Ernst von Hohenstein. It was proclaimed in Mansfelder Land (district), Mansfelder Land and in the mining areas of Saxony and miners were invited to dig for silver and other metals. Natural monuments ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oberstein
Idar-Oberstein () is a town in the Birkenfeld district in Rhineland-Palatinate, Germany. As a ''Große kreisangehörige Stadt'' (large city belonging to a district), it assumes some of the responsibilities that for smaller municipalities in the district are assumed by the district administration. Today's town of Idar-Oberstein is the product of two rounds of administrative reform, one in 1933 and the other in 1969, which saw many municipalities amalgamated into one. The various '' Stadtteile'' have, however, retained their original identities, which, aside from the somewhat more urban character encountered in Idar and Oberstein, tend to hearken back to each centre's history as a rural village. Idar-Oberstein is known as a gemstone town, and also as a garrison town. It is also the largest town in the Hunsrück. Geography The town lies on the southern edge of the Hunsrück on both sides of the river Nahe. Constituent communities The following are the divisions within the town ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
