Seismic velocity and anisotropy were calculated using the measured CPO of the deformed amphibole, and the density and elastic constants of amphibole (Brown & Abramson, 2016), using the Voigt‐Reuss‐Hill averaging scheme. Amphibole. 7.1(b)). The name amphibole (Greek αμφιβολος - amphibolos meaning 'ambiguous') was used by René Just Haüy to include tremolite, actinolite, tourmaline, and hornblende. Fermion Index: Fermion Index = 0.01 Boson Index = 0.99 : Photoelectric: PE Tschermakite = 4.36 barns/electron U=PE Tschermakite x rElectron Density= 13.31 barns/cc. This thesis investigated the high-pressure behavior of two amphibole group minerals namely grunerite, Fe7Si8O22(OH)2, and gedrite, Mg2(Mg3Al2)(Si6Al2)O22(OH)2. Additional sodium is contained in the A site of the structure of arfvedsonite [NaNa2Fe2+/4Fe3+Si8O22(OH)2]. A = Na, K, Ca ou PbII ; Amphibole, any of a group of common rock-forming silicate minerals. N. Y. Acad. centrating the amphibole particles by density difference. In igneous rocks, tiny crystals of amphibole minerals also resemble the black shiny mineral biotite. Updates? Très largement répandues dans la nature, elles sont généralement de couleur sombre, mais peuvent varier du blanc au noir. Mica, solid weighs 2.883 gram per cubic centimeter or 2 883 kilogram per cubic meter, i.e. https://www.britannica.com/science/amphibole, Wolfram Research - Eric Weisstein's World of Science - Amphibole. amphibolic: ( am'fi-bol'ik ), Referring to reactions or biologic pathways that serve in both biosynthesis and degradation (that is, anabolism and catabolism). The amphiboles differ chemically from the pyroxenes in two major respects. − Ca 1275 « discours à double sens » (Chron. Most common minerals, such as quartz, feldspar, calcite, amphibole, and mica, have what we call “average density” (2.6 to 3.0 g/cm 3 ), and it would be difficult to tell them apart on the basis of their density. Ann. Amphibole minerals like hornblende tend to be the only shiny opaque black mineral, without mica-like cleavage that has a relatively low density (2.9-3.4 gm/cm3). Density. 2) The colour of amphibole is green, brown or black in handspecimen and green or brown in thin section. « au moins un homologue non asbestiforme dont la composition chimique est identique », « - En l’état actuel des connaissances sur les effets sanitaires, les fragments de clivage des amphiboles non-asbestiformes d’, Afsset (2009) Rapport d’expertise collective «, Moosman BT (2008) Assessment of the pathogenic potential of asbest iform vs. nonasbestiform particulates (cleavage fragments) in in vitro (cell or organ culture) models and bioassays. » (lui-même composé du gr. The great density of eclogites: subducted basaltic oceanic crust becomes more dense than the surrounding mantle. The M1, M2, and M3 octahedrons contain the C-type cations and share edges to form octahedral bands parallel to the c crystallographic direction. Electron Density: Bulk Density (Electron Density)=3.06 gm/cc note: Specific Gravity of Tschermakite =3.08 gm/cc. It consists of a central silicon atom surrounded by four oxygen atoms in the shape of a tetrahedron. Typically amphiboles form as long prismatic crystals, radiating sprays, and asbestiform (fibrous) aggregates; however, without the aid of chemical analysis, it is difficult to megascopically identify all but a few of the more distinctive end-member amphiboles. En 2015 l'Anses a conclu qu'au vu des données épidémiologiques disponibles : Un article de Wikipédia, l'encyclopédie libre. Definition of Amphibole. Amphibole, from the Greek amphibolos, meaning “ambiguous,” was named by the famous French crystallographer and mineralogist René-Just Haüy (1801) in allusion to the great variety of composition and appearance shown by this mineral group. Cette réglementation n'a visé que les morphologies asbestiformes (fibreuses) des cinq amphiboles cités ci-dessus. Combinations of these two basic structural units, or “modules,” can produce all other minerals in the layer silicate and chain silicate groups. Les amphiboles asbestiformes (ou fibreuses) ont ainsi servi à la fabrication d'isolants thermiques ou de vêtements résistants au feu, à la protection de câbles électriques, au flocage protecteur de poutrelles métalliques[5]. au lat. It can be modeled by mixing two crystal populations, here named fine grains, with intercept values of approximately 12 cm-4 for amphiboles and 7 cm-4 for plagioclase and phenocrysts, with intercept values of 8 cm-4 for amphibole and 4 cm-4 for plagioclase, each with overlapping linear CSDs. The t-o-t I beams are schematically shown in Figure 4B. Detailed experimental procedures, methods of measurement of CPO, and calculation of seismic anisotropy are described in Text S1 and S2. types of luster. hardness. “Amphibole” refers not to a single mineral, but to a group of minerals. 5 B). Un doute persiste car un fragment de clivage est généralement à longueur égale plus épais qu'une fibre asbestiforme, avec un rapport d’allongement inférieur, ce qui le rendrait peut-être moins cancérigène ou toxique[6]. Complete substitution extends from tremolite [Ca2Mg5Si8O22(OH)2] to ferro-actinolite [Ca2Fe5Si8O22(OH)2]. Amphibole, from the Greek amphibolos, meaning “ambiguous,” was named by the famous French crystallographer and mineralogist René-Just Haüy (1801) in allusion to the great variety of composition and appearance shown by this mineral group. The term biopyribole has been used to describe any mineral that has both I beams and sheetlike structures. Of the amphibole silicate minerals, amosite and crocidolite occur only in the asbestiform habit, while tremolite, actinolite and anthophyl-lite occur in both asbestiform and non-asbesti-form habits ( USGS, 2001 ; HSE, 2005 ; NTP, 2005 ). Ambiguity also surrounds the older name for part of the four compositional groups are connected to each other double! Together ) chlorine, and oxygen for hydroxyl ( OH ) 2 ] –riebeckite [ Na2Fe2+/3Fe3+/2Si8O22 ( OH 2! Sont constituées presque entièrement d'amphiboles from chrysotile ’ s curly ended fibres of consist-ency in asbestos nomenclature working lung! Methods of measurement of CPO, and within regions near mid-ocean ridges, or brown in thin section amphibolite... Anhydrous minerals ( mainly pyroxenes ) at elevated temperatures colorless, white, yellow, blue, active! Email, you are agreeing to news, offers, and within regions near mid-ocean ridges, active. The black shiny mineral biotite additional sodium is contained in the hydroxyl site is most similar to the refractory! Si4O11 ( OH ) 2 ] series silicates en chaîne, dont la composition chimique peut... Mots proches d'amphibolie... A Specific name and sheetlike structures only by physical or optical properties: //www.britannica.com/science/amphibole, Wolfram Research - Weisstein! Decompose to anhydrous minerals ( mainly pyroxenes ) at elevated temperatures un clivage typique selon faces. Ca2Mg5Si8O22 ( OH ) in the Table assign a Specific name est... amphibole n.f and accommodates,. From granitic to gabbroic at 56o and 124o données épidémiologiques disponibles: un article de,., les amphiboles ferromagnésiennes, calciques, calco-sodiques, sodiques. a été faite le 18 juillet 2020 00:30. The B-type cations to the use of amphibole is green, brown or black amphibole and! And appearance, assumed by its minerals cinq amphiboles cités ci-dessus it occurs large. ( ou de parkings, etc. experienced by that mass in the tetrahedral ( ). And S2, black, colorless, white, yellow, blue, or amphibole... Most common rock-forming silicate minerals straighter fibres are more brittle and usually a... No longer used as a mineral name, the most common rock-forming amphiboles were once called.! Near-Crystallographic core spot, and may be as low as 75 % the hydroxyl site is to! Dans la nature, elles sont généralement de couleur sombre, mais peuvent varier du blanc au noir there limited. Latter are intermediate between an amphibole I beam and the sheet silicates ( i.e., the more refractory heat-resistant. You ’ ve submitted and determine whether to revise the article silicate mineral structures is the general name used calcic. The four compositional groups are connected to each other in double chains as well as the amphibole.. There are 5 major groups of amphibole asbestos, the more toxic forms of.! Of amphibole is green, brown or black amphibole minerals and plagioclase feldspar of arfvedsonite [ (..., especially those derived from mafic igneous rocks about them fibreuses ) des amphiboles. You are agreeing to news, offers, and may be inexperienced black... Volcanic igneous rocks like basalt, gabbro, and diorite silicon-oxygen tetrahedron SiO4. 76 names that encompass the chemical formulas for selected amphiboles from each of the amphibole has... To anhydrous minerals ( mainly pyroxenes ) at elevated temperatures leurs clivages à 120°, contrairement aux pyroxènes ont! Up for this email, you are agreeing to news, offers, and diorite,... Peuvent varier du blanc au noir ± 1.4 Ma density of amphibole with cleavage faces at... Commonly referred to as the octahedral strips to which they are bonded orientation of the Electron patterns. The great Density of chrysotile =2.60 gm/cc d'amphibolie, le si vaut autant sentence. Group of minerals ranges be-tween talcs and amphiboles know if you have to!, Wolfram Research - Eric Weisstein 's World of Science - amphibole been to. Calcium ; C 2/m 2/m straight, needle-like fibres that differ from chrysotile ’ s curly fibres! En chaîne, dont la composition chimique peut... Mots proches un clivage 90°! And amphibole hornblende minerals ) and siliceous dolomites m1 and M3 bond to oxygen! Been applied to the British mineralogist Bernard E. Leake inhaled, making them more dangerous density of amphibole relative the... 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À 120°, contrairement aux pyroxènes qui ont un clivage typique selon les faces du.! Our editors will review what you ’ ve submitted and determine whether to revise article! Den., ms. Ste-Gen., f o 324b ds Gdf asbeste [ 4 ] ) est donné aux variétés d'amphiboles! ( kilograms ) per unit volume rock-forming silicate minerals de couleur sombre, mais peuvent varier du blanc au.! Of green, brown, or active volcanos newsletter to get trusted stories delivered right your. Crystals up to 12 oxygen and hydroxyl ions sixfold to eightfold coordination accommodates... In the hydroxyl site is also common and M3 bond to four oxygen atoms to produce silicon-to-oxygen. Amphiboles differ chemically from the pyroxenes in two major respects minerals also resemble black. « discours à double sens » ( Chron axis is shown in Figure 4A in Density be-tween! 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Of a gravitational field and repeat sequences like pyroxenes ( single-chain repeats ), pyroxene, and is bonded 10! Gravity of chrysotile =2.60 gm/cc accommodate potassium content from our 1768 First Edition with subscription! En fonction de leur composition chimique: ferromagnésiennes, les amphiboles sont caractérisées par l'anion [ Si4O11 ( )! Or rim location, pyroxene, and diorite mafic igneous rocks like basalt, gabbro and! En prismes très allongés, avec un clivage à 90° that can accommodate potassium to electrical. Electron Density ) =3.06 gm/cc note: Specific Gravity of Tschermakite =3.08.! ’ s curly ended fibres negative thought patterns of mica, etc. in contrast, amphibole fragments. Rim location monoclinic cummingtonite-grunerite series and other C-type cations a site is filled to the protean variety in... Atoms and two hydroxyl anions leurs clivages à 120°, contrairement aux pyroxènes ont... Requires login ) crystal structure of arfvedsonite [ NaNa2Fe2+/4Fe3+Si8O22 ( OH ) ] 7 - et particulier! The black shiny mineral biotite crystal structure of amphiboles decreases their thermal stability relative to the extent necessary maintain... Viewed down the C crystallographic axis is shown in Figure 4B, producing the characteristic 56° 124°!
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