OSHA PEL (United … Glaucophane and riebeckite are usually blue. Typically observed in hues of beige, tan, and brown, amosite is mineralogically known as asbestiform grunerite or from the amphibole cummingtonite-grunerite mineral series. However the … Was extracted from approximately 80,000 tons of amosite in the province of Transvaal in South Africa by the year 1970. It is often referred to as “brown Asbestos” because of its color. Significance in the Environment: Amosite is a hazardous material and exposure should be very carefully limited. The crystals are monoclinic prismatic. Amosite asbestos is a less common form of asbestos and is also known as brown asbestos or Grunerite. There are various morphological types that differ in their mechanical, chemical and toxicological properties [1–3]. Anthophyllite is gray to various shades of green and brown. The mineral cummingtonite, is basically the middle member of the Cummingtonite Series, which include the minerals grunerite and magnesiocummingtonite. colour and pleochroism (colour in relation to the orientation of the polarised light) can be observed. 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. Cummingtonite is the name of a series as well as the name of a mineral. The cummingtonite-grunerite series occurs in various shades of light brown. It was at one time, … 20cm x 6.5cm x 6cm Grunerite, Hematite (Var: Specularite) Asbestos, any of several minerals that readily separate into long, flexible fibres. Riebeckite asbestos is also known as crocidolite or blue asbestos while grunerite asbestos is known as amosite or brown asbestos. The commercial production of amosite, or “brown” asbestos, ended within the last decade and this type of asbestos is no longer mined. 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. Other asbestos types are less pleochroic, with actinolite usually pale green (parallel) and amosite light brown. This type of asbestos is particularly strong and heat resistant, as well as possessing extreme insulation … The Mohs hardness is 5 to 6 and the specific gravity is 3.4 to 3.5. Amosite asbestos also called as brown asbestos, due to its gray to brown color, or Grunerite. 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. 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. 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 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. For each grunerite spectrum, the peaks are listed below with all assignments. The analyser is then inserted (to give crossed- Table 1 lists those that com… [ Top] [ Japanese] Grunerite [abbr. Amosite was used industrially for various purposes such as cement sheet and pipe … If the morphology matches amosite, examine the fibers using the dispersion staining objective. Its chemical composition is (Mg, Fe, Mn) 7 [Si 8 O 22](OH) 2. Iron-free varieties of tremolite containing manganese can have a lavender colour. Crocidolite appears blue (parallel) and grey (perpendicular). Asbestos, Amosite (CAS NO.12172-73-5) was discovered in 1853 and named for Louis Gruner, a Swiss-French chemist who first analysed it. Asbestos is a generic term for a group of crystalline mineral silicates that occur naturally in various forms. 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. TWA: 0.1 f/cc 8 hours. Aspect ratio typically >10:1. The seams break down readily to yield long, somewhat harsh fibers, brownish-yellow to almost white in color depending … Amosite: Amosite asbestos is primarily sourced in South Africa. The luster is glassy to pearly with colors ranging from green, brown to dark grey. • Some confusion has arisen over the definition of amphibole asbestos which has Commonly known as brown asbestos, the texture of amosite fibres is characterised by their sharp, brittle, needle-like fibres and brownish-grey colour. Tremolite … It is the next most common commercial asbestos after Chrysotile. A narrow translucent quartz vein crosses the middle of the specimen. If amosite is confirmed by this test, go to step 15 for quantitative estimation, otherwise continue. 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 … The luster is glassy to pearly with colors ranging from green, brown to dark grey. Amosite was commonly mined in South Africa in its natural type, Grunerite. The crystals are monoclinic prismatic. The luster is glassy to pearly with colors ranging from green, brown to dark grey. Include approximate length and width of fibers, color, and general appearance. 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). White or greenish (chrysotile), blue (crocidolite), or gray-green (amosite) fibrous, odorless solids. It was discovered in 1853 and named after Emmanuel-Louis Gruner (1809–1883), a Swiss-French chemist who first analysed it. In its natural state, amosite is known as grunerite, and it was mainly mined in South Africa. 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 Fiber bundles have splayed ends and “kinks”. Shows shiny splays silver, gold and rose coloured. 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. Amosite’s distinctive brown or earthy grey colour comes from its high iron content. The Mohs hardness is 5 to 6 and the specific gravity is 3.4 to 3.5. Grunerite is monoclinic and typically weakly colored in green or brown in plane light. It was discovered in 1853 and named after Emmanuel-Louis Gruner (1809–1883), a Swiss-French chemist who first analyzed it. 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 … In its natural state and is known as amosite mineral grunerite commercially referred to as grunerite asbestos amosite, or brown. 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 Amosite is characterized by its straight brittle fibers and utilized for cement sheeting and pipe insulation. Iron-rich grunerite fibers may have colors ranging from very pale yellow to light brown. It often appears brown in color and its fibers are shorter and straighter than chrysotile fibers. Blue and pale blue colors indicate the cummingtonite form of amosite, and gold and blue colors indicate the grunerite form of amosite.