The Mohs hardness is 5 to 6 and the specific gravity is 3.4 to 3.5. The luster is glassy to pearly with colors ranging from green, brown to dark grey. Gru ] Year of discovery: 1853 (Sarvengude ravine, France), 1894 (Japan) Locality list: 18 localities of grunerite Fe 7 Si 8 O 22 (OH) 2 [][Fe 2+ 2][Fe 2+ 5][(OH) 2 |(Si 4 O 11) 2] 14-; Class: Mg-Fe-Mn amphibole subgroup w(OH,F,Cl)-dominant amphibole group Amphibole supergroup Class: … It often appears brown in color and its fibers are shorter and straighter than chrysotile fibers. The luster is glassy to pearly with colors ranging from green, brown to dark grey. Glaucophane and riebeckite are usually blue. i. Include approximate length and width of fibers, color, and general appearance. Riebeckite asbestos is also known as crocidolite or blue asbestos while grunerite asbestos is known as amosite or brown asbestos. It was discovered in 1853 and named after Emmanuel-Louis Gruner (1809–1883), a Swiss-French chemist who first analyzed it. The crystals are monoclinic prismatic. The regulated amphiboles are often referred to by generic names. • Some confusion has arisen over the definition of amphibole asbestos which has The cummingtonite-grunerite series occurs in various shades of light brown. Grunerite became commercially known as amosite because one of the most important suppliers of this form of asbestos was the Asbestos Mines of South Africa or AMOSA as these mines were commonly called. The seams break down readily to yield long, somewhat harsh fibers, brownish-yellow to almost white in color depending … Crocidolite appears blue (parallel) and grey (perpendicular). However the … In its natural state, amosite is known as grunerite, and it was mainly mined in South Africa. The magnesium-rich end member of the cummingtonite-grunerite series is colorless and non-pleochroic, but the pleochroism increases with Fe/ Mg ratio. amphiboles, for example grunerite (amosite), riebeckite (crocidolite), tremolite, actinolite and anthophyllite may occasionally occur in asbestos forms although these are rare in comparison to the normal varieties. Aspect ratio typically >10:1. Its chemical composition is (Mg, Fe, Mn) 7 [Si 8 O 22](OH) 2. Other asbestos types are less pleochroic, with actinolite usually pale green (parallel) and amosite light brown. Grunerite is also known commercially by the name amosite from the name Asbestos Mines Of … They result when siliceous minerals are leached out of rock by water and then re-crystallize in spaces within the parent rock as compound metallic silicates. Grunerite (Amosite) Texture: asbestiform(a) Color: grey-brown in hand specimen, α′ colorless, γ′ colorless to very light brown Birefringence: medium (nγ′ - nα′ = 0.023) (b) Extinction: mostly parallel Sign of Elongation: positive Concentration of Asbestos(c): > 90 % by weight or volume In its natural state and is known as amosite mineral grunerite commercially referred to as grunerite asbestos amosite, or brown. White or greenish (chrysotile), blue (crocidolite), or gray-green (amosite) fibrous, odorless solids. The commercial production of amosite, or “brown” asbestos, ended within the last decade and this type of asbestos is no longer mined. Chrysotile, the fibrous form of the mineral serpentine, is the best-known type and accounts for about 95 percent of all asbestos in commercial use.It is a hydrous magnesium silicate with the chemical composition of Mg 3 Si 2 O 5 (OH) 4.The … Amosite is characterized by its straight brittle fibers and utilized for cement sheeting and pipe insulation. The crystals are monoclinic prismatic. Amosite: Amosite asbestos is primarily sourced in South Africa. Amosite asbestos also called as brown asbestos, due to its gray to brown color, or Grunerite. Amosite asbestos is another member of the amphibole family, being the fibrous variety of the mineral grunerite, a ferrous magnesium silicate having the chemical formula 1.5Mg0 5.5Fe0 8SiO2 H20. The colour is caused by the dominant iron rich grunerite, with quartz, and reddish brown iron rich riebeckite. Amosite asbestos is the fibrous form of amphibole in the cummingtonite-grunerite family. “Amosite” is derived from the term “AMOSA”, a shortened form of Asbestos Mines of South Africa (Ross et al., 1984). Anthophyllite is gray to various shades of green and brown. If amosite is confirmed by this test, go to step 15 for quantitative estimation, otherwise continue. The luster is glassy to pearly with colors ranging from green, brown to dark grey. The analyser is then inserted (to give crossed- This type of asbestos is particularly strong and heat resistant, as well as possessing extreme insulation … Asbestos pipe insulation in buildings - used on heating pipes, water pipes, and on occasion drains - How to make a visual identification of asbestos insulation without laboratory tests Asbestos pipe insulation, still in use or abandoned on building pipes, compared with fiberglass pipe insulation Asbestos pipe insulation, insulated over … Amosite asbestos is a less common form of asbestos and is also known as brown asbestos or Grunerite. Also called Grunerite or brown asbestos, amosite asbestos is an amphibole originating in Africa. Asbestos, Amosite (CAS NO.12172-73-5) was discovered in 1853 and named for Louis Gruner, a Swiss-French chemist who first analysed it. Amosite Asbestos The U.S. Environmental Protection Agency determined amosite, or “brown asbestos,” to be the second most commonly used type of asbestos in the United States. Asbestos, any of several minerals that readily separate into long, flexible fibres. It is the next most common commercial asbestos after Chrysotile. colour and pleochroism (colour in relation to the orientation of the polarised light) can be observed. Commonly known as brown asbestos, the texture of amosite fibres is characterised by their sharp, brittle, needle-like fibres and brownish-grey colour. The mineral cummingtonite, is basically the middle member of the Cummingtonite Series, which include the minerals grunerite and magnesiocummingtonite. TWA: 0.1 f/cc 8 hours. A narrow translucent quartz vein crosses the middle of the specimen. Asbestos is a generic term for a group of crystalline mineral silicates that occur naturally in various forms. Grunerite is monoclinic and typically weakly colored in green or brown in plane light. Blue and pale blue colors indicate the cummingtonite form of amosite, and gold and blue colors indicate the grunerite form of amosite. Amosite Asbestos. Asbestos, Amosite Asbestos, grunerite ACGIH TLV (United States, 3/2019). It is often referred to as “brown Asbestos” because of its color. Amosite asbestos, also known as “brown asbestos” and grunerite, is a type of amphibole asbestos. Iron-free varieties of tremolite containing manganese can have a lavender colour. For each grunerite spectrum, the peaks are listed below with all assignments. It was discovered in 1853 and named after Emmanuel-Louis Gruner (1809–1883), a Swiss-French chemist who first analysed it. [ Top] [ Japanese] Grunerite [abbr. These spectra are very similar – the ν 1 (A 1g ) symmetric stretching (ν s ) of the Si-O b -Si bridge is shown in all spectra (fig. Amosite’s distinctive brown or earthy grey colour comes from its high iron content. Amosite. Form: Respirable fibers: length greater than 5 uM; aspect ratio equal to or greater than 3:1 as determined by the membrane filter method at 400-450X magnification (4-mm objective) phase contrast illumination. Table 1 lists those that com… If the morphology matches amosite, examine the fibers using the dispersion staining objective. The name derives from the origin where most of this mineral was mined, in the Asbestos Mines of South Africa. Was extracted from approximately 80,000 tons of amosite in the province of Transvaal in South Africa by the year 1970. Amosite was commonly mined in South Africa in its natural type, Grunerite. 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