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Datolite
Datolite is a calcium boron hydroxide nesosilicate, Ca B Si O4(O H). It was first observed by Jens Esmark in 1806, and named by him from δατεῖσθαι, "to divide," and λίθος, "stone," in allusion to the granular structure of the massive mineral. Datolite crystallizes in the monoclinic system forming prismatic crystals and nodular masses. The luster is vitreous and may be brown, yellow, light green or colorless. The Mohs hardness is 5.5 and the specific gravity is 2.8 - 3.0. The type localities are in the diabases of the Connecticut River valley and Arendal, Aust-Agder, Norway. Associated minerals include prehnite, danburite, babingtonite, epidote, native copper, calcite, quartz and zeolites. It is common in the copper deposits of the Lake Superior region of Michigan. It occurs as a secondary mineral in mafic igneous rocks often filling vesicles along with zeolites in basalt. Unlike most localities throughout the world, the occurrence of datolite in the Lake Superio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jens Esmark
Jens Esmark (31 January 1763 – 26 January 1839) was a Danish-Norwegian professor of mineralogy who contributed to many of the initial discoveries and conceptual analyses of glaciers, specifically the concept that glaciers had covered larger areas in the past. Biography Jens Esmark was born in Houlbjerg in Århus, Denmark. Esmark moved to Norway to the silver mining community of Kongsberg. He studied at the local mining academy. He completed his subsequent studies in Copenhagen and was accepted as a surveyor. Starting in 1797, Esmark was employed as a lecturer in mineralogy at the Kongsberg Mining Academy. In 1814, Esmark became Norway's first professor of geology as a professor of geology at the University of Oslo, and was described as "a pioneer in glacial geology", by professor of Quaternary geology and Glaciology Bjørn G. Andersen. In 1798, Esmark was the first person to ascend Snøhetta, highest in the mountain range Dovrefjell in southern Norway. The same year he l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehnite
Prehnite is an inosilicate of calcium and aluminium with the formula: Ca2Al(AlSi3O10)(OH)2. Limited Fe3+ substitutes for aluminium in the structure. Prehnite crystallizes in the orthorhombic crystal system, and most often forms as stalactitic or botryoidal aggregates, with only just the crests of small crystals showing any faces, which are almost always curved or composite. Very rarely will it form distinct, well-individualized crystals showing a square-like cross-section, including those found at the Jeffrey Mine in Asbestos, Quebec, Canada. Prehnite is brittle with an uneven fracture and a vitreous to pearly luster. Its hardness is 6-6.5, its specific gravity is 2.80-2.90 and its color varies from light green to yellow, but also colorless, blue, pink or white. In April 2000, rare orange prehnite was discovered in the Kalahari Manganese Fields, South Africa. Prehnite is mostly translucent, and rarely transparent. Though not a zeolite, prehnite is found associated with minerals suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nesosilicate
Silicate minerals are rock-forming minerals made up of silicate groups. They are the largest and most important class of minerals and make up approximately 90 percent of Earth's crust. In mineralogy, silica (silicon dioxide, ) is usually considered a silicate mineral. Silica is found in nature as the mineral quartz, and its polymorphism (materials science), polymorphs. On Earth, a wide variety of silicate minerals occur in an even wider range of combinations as a result of the processes that have been forming and re-working the crust for billions of years. These processes include partial melting, crystallization, fractionation, metamorphism, weathering, and diagenesis. Living organisms also contribute to this carbonate–silicate cycle, geologic cycle. For example, a type of plankton known as diatoms construct their exoskeletons ("frustules") from silica extracted from seawater. The frustules of dead diatoms are a major constituent of deep ocean sediment, and of diatomaceous e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diabase
Diabase (), also called dolerite () or microgabbro, is a mafic, holocrystalline, subvolcanic rock equivalent to volcanic basalt or plutonic gabbro. Diabase dikes and sills are typically shallow intrusive bodies and often exhibit fine-grained to aphanitic chilled margins which may contain tachylite (dark mafic glass). ''Diabase'' is the preferred name in North America, while ''dolerite'' is the preferred name in the rest of the English-speaking world, where sometimes the name ''diabase'' refers to altered dolerites and basalts. Some geologists prefer to avoid confusion by using the name ''microgabbro''. The name ''diabase'' comes from the French ', and ultimately from the Greek - meaning "act of crossing over, transition". Petrography Diabase normally has a fine but visible texture of euhedral lath-shaped plagioclase crystals (62%) set in a finer matrix of clinopyroxene, typically augite (20–29%), with minor olivine (3% up to 12% in olivine diabase), magnetite (2%), an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Superior
Lake Superior in central North America is the largest freshwater lake in the world by surface areaThe Caspian Sea is the largest lake, but is saline, not freshwater. and the third-largest by volume, holding 10% of the world's surface fresh water. The northern and westernmost of the Great Lakes of North America, it straddles the Canada–United States border with the province of Ontario to the north and east, and the states of Minnesota to the northwest and Wisconsin and Michigan to the south. It drains into Lake Huron via St. Marys River, then through the lower Great Lakes to the St. Lawrence River and the Atlantic Ocean. Name The Ojibwe name for the lake is ''gichi-gami'' (in syllabics: , pronounced ''gitchi-gami'' or ''kitchi-gami'' in different dialects), meaning "great sea". Henry Wadsworth Longfellow wrote this name as "Gitche Gumee" in the poem ''The Song of Hiawatha'', as did Gordon Lightfoot in his song " The Wreck of the ''Edmund Fitzgerald''". According to oth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zeolite
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 ï½¥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 ob ... [...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] |
Calcite
Calcite is a Carbonate minerals, carbonate mineral and the most stable Polymorphism (materials science), polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on the Mohs scale of mineral hardness, based on Scratch hardness, scratch hardness comparison. Large calcite crystals are used in optical equipment, and limestone composed mostly of calcite has numerous uses. Other polymorphs of calcium carbonate are the minerals aragonite and vaterite. Aragonite will change to calcite over timescales of days or less at temperatures exceeding 300 °C, and vaterite is even less stable. Etymology Calcite is derived from the German ''Calcit'', a term from the 19th century that came from the Latin word for Lime (material), lime, ''calx'' (genitive calcis) with the suffix "-ite" used to name minerals. It is thus etymologically related to chalk. When applied by archaeology, archaeologists and stone trade pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copper
Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orange color. Copper is used as a conductor of heat and electricity, as a building material, and as a constituent of various metal alloys, such as sterling silver used in jewelry, cupronickel used to make marine hardware and coins, and constantan used in strain gauges and thermocouples for temperature measurement. Copper is one of the few metals that can occur in nature in a directly usable metallic form ( native metals). This led to very early human use in several regions, from circa 8000 BC. Thousands of years later, it was the first metal to be smelted from sulfide ores, circa 5000 BC; the first metal to be cast into a shape in a mold, c. 4000 BC; and the first metal to be purposely alloyed with another metal, tin, to create ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epidote
Epidote is a calcium aluminium iron sorosilicate mineral. Description Well developed crystals of epidote, Ca2Al2(Fe3+;Al)(SiO4)(Si2O7)O(OH), crystallizing in the monoclinic system, are of frequent occurrence: they are commonly prismatic in habit, the direction of elongation being perpendicular to the single plane of symmetry. The faces are often deeply striated and crystals are often twinned. Many of the characters of the mineral vary with the amount of iron present for instance, the color, the optical constants, and the specific gravity. The color is green, grey, brown or nearly black, but usually a characteristic shade of yellowish-green or pistachio-green. It displays strong pleochroism, the pleochroic colors being usually green, yellow and brown. Clinozoisite is green, white or pale rose-red group species containing very little iron, thus having the same chemical composition as the orthorhombic mineral zoisite. The name, due to Haüy, is derived from the Greek word "epidos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Babingtonite
Babingtonite is a calcium iron manganese inosilicate mineral with the formula Ca2( Fe, Mn)Fe Si5 O14(O H). It is unusual in that iron(III) completely replaces the aluminium so typical of silicate minerals. It is a very dark green to black translucent (in thin crystals or splinters) mineral crystallizing in the triclinic system with typically radial short prismatic clusters and druzy coatings. It occurs with zeolite minerals in cavities in volcanic rocks. Babingtonite contains both iron(II) and iron(III) and shows weak magnetism. It has a Mohs hardness of 5.5 to 6 and a specific gravity of 3.3. It was first described in 1824 from samples from Arendal, Aust-Agder, Norway (which is its type locality) and was named after the Irish physician and mineralogist William Babington (1757–1833). It is the official mineral (mineral emblem) of the Commonwealth of Massachusetts. The first published report of babingtonite in Massachusetts was by Francis Alger in 1844, who credited Thomas Nu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Danburite
Danburite is a calcium boron silicate mineral with a chemical formula of CaB2(SiO4)2. It has a Mohs hardness of 7 to 7.5 and a specific gravity of 3.0. The mineral has an orthorhombic crystal form. It is usually colourless, like quartz, but can also be either pale yellow or yellowish-brown. It typically occurs in contact metamorphic rocks. The Dana classification of minerals categorizes danburite as a sorosilicate, while the Strunz classification scheme lists it as a tectosilicate; its structure can be interpreted as either. Its crystal symmetry and form are similar to topaz; however, topaz is a calcium fluorine bearing nesosilicate. The clarity, resilience, and strong dispersion of danburite make it valuable as cut stones for jewelry. It is named for Danbury, Connecticut, United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 state ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
