If the morphology matches amosite, examine the fibers using the dispersion staining objective. Blue and pale blue colors indicate the cummingtonite form of amosite, and gold and blue colors indicate the grunerite form of amosite. Asbestos is a generic term for a group of crystalline mineral silicates that occur naturally in various forms. Iron-free varieties of tremolite containing manganese can have a lavender colour. 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 mineral cummingtonite, is basically the middle member of the Cummingtonite Series, which include the minerals grunerite and magnesiocummingtonite. Amosite was also historically known as: "brown asbestos". Table 1 lists those that com… Amosite was used industrially for various purposes such as cement sheet and pipe … Grunerite is monoclinic and typically weakly colored in green or brown in plane light. 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. Amosite. “Amosite” is derived from the term “AMOSA”, a shortened form of Asbestos Mines of South Africa (Ross et al., 1984). The crystals are monoclinic prismatic. Amosite was commonly mined in South Africa in its natural type, Grunerite. Its chemical composition is (Mg, Fe, Mn) 7 [Si 8 O 22](OH) 2. Riebeckite asbestos is also known as crocidolite or blue asbestos while grunerite asbestos is known as amosite or brown asbestos. Amosite asbestos also called as brown asbestos, due to its gray to brown color, or Grunerite. Amosite’s distinctive brown or earthy grey colour comes from its high iron content. 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 … Tremolite … 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. Morphology, color a Refractive indices b Birefring- ence Extinction Sign of elonation; α γ; Chrysotile (asbestiform serpentine) Wavy fibers. It was discovered in 1853 and named after Emmanuel-Louis Gruner (1809–1883), a Swiss-French chemist who first analysed it. Fiber bundles have splayed ends and “kinks”. 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 … The colour is caused by the dominant iron rich grunerite, with quartz, and reddish brown iron rich riebeckite. These include the serpentine mineral chrysotile (also known as ‘white asbestos’), and the five amphibole minerals – actinolite, amosite (also known as ‘brown asbestos’), anthophyl- lite, crocidolite (also known as ‘blue asbestos’), and tremolite (IARC, 1973; USGS, 2001). The magnesium-rich end member of the cummingtonite-grunerite series is colorless and non-pleochroic, but the pleochroism increases with Fe/ Mg ratio. The luster is glassy to pearly with colors ranging from green, brown to dark grey. Cummingtonite is the name of a series as well as the name of a mineral. Significance in the Environment: Amosite is a hazardous material and exposure should be very carefully limited. Amosite Asbestos. The cummingtonite-grunerite series occurs in various shades of light brown. Grunerite is a mineral of the amphibole group of minerals with formula Fe 7 Si 8 O 22 2.It is the iron endmember of the grunerite-cummingtonite series.It forms as fibrous, columnar or massive aggregates of crystals. Typically observed in hues of beige, tan, and brown, amosite is mineralogically known as asbestiform grunerite or from the amphibole cummingtonite-grunerite mineral series. Glaucophane and riebeckite are usually blue. General Grunerite Information : Chemical Formula: [ ]Fe++7Si8O22(OH)2 : Composition: Molecular Weight = 1,001.61 gm Iron 39.03 % Fe 50.21 % FeO: Silicon 22.43 % Si 47.99 % SiO 2: Hydrogen 0.20 % H 1.80 % H 2 O: Oxygen 38.34 % O: 100.00 % 100.00 % = TOTAL OXIDE 4, see reference paper) around 660 cm -1 , more exactly at 665 cm -1 for the grunerite samples of this work and at 663 cm -1 and … The luster is glassy to pearly with colors ranging from green, brown to dark grey. A narrow translucent quartz vein crosses the middle of the specimen. However the … Include approximate length and width of fibers, color, and general appearance. Amosite. Grunerite is also known commercially by the name amosite from the name Asbestos Mines Of … Anthophyllite is gray to various shades of green and brown. It often appears brown in color and its fibers are shorter and straighter than chrysotile fibers. 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. 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. Amosite asbestos is the fibrous form of amphibole in the cummingtonite-grunerite family. Asbestos, any of several minerals that readily separate into long, flexible fibres. 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. TWA: 0.1 f/cc 8 hours. Was extracted from approximately 80,000 tons of amosite in the province of Transvaal in South Africa by the year 1970. The crystals are monoclinic prismatic. 20cm x 6.5cm x 6cm Grunerite, Hematite (Var: Specularite) i. It is the next most common commercial asbestos after Chrysotile. White or greenish (chrysotile), blue (crocidolite), or gray-green (amosite) fibrous, odorless solids. The analyser is then inserted (to give crossed- This type of asbestos is particularly strong and heat resistant, as well as possessing extreme insulation … Grunerite Crystallography: Axial Ratios: a:b:c =0.5252:1:0.2925 : Cell Dimensions: a = 9.57, b = 18.22, c = 5.33, Z = 2; beta = 102.1° V = 908.72 Den(Calc)= 3.66 Crocidolite appears blue (parallel) and grey (perpendicular). The luster is glassy to pearly with colors ranging from green, brown to dark grey. Aspect ratio typically >10:1. The name derives from the origin where most of this mineral was mined, in the Asbestos Mines of South Africa. It is often referred to as “brown Asbestos” because of its color. All three minerals' formulae are essentially the same: (Mg, Fe)7Si8O22(OH)2. Iron-rich grunerite fibers may have colors ranging from very pale yellow to light brown. 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