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29-477: This page is about the gemstone. For the type of asbestos, see chrysotile . For the aluminium ore and processing agent, see cryolite . [REDACTED] Look up chrysolite in Wiktionary, the free dictionary. Chrysolite may refer to: Peridot , a gem-quality olivine Archaically, any of several green or yellow-green-coloured gemstones including Topaz ,

58-512: A tensometer at a constant strain (change in gauge length divided by initial gauge length) rate until the sample breaks. When testing some metals, indentation hardness correlates linearly with tensile strength. This important relation permits economically important nondestructive testing of bulk metal deliveries with lightweight, even portable equipment, such as hand-held Rockwell hardness testers. This practical correlation helps quality assurance in metalworking industries to extend well beyond

87-578: A human carcinogen by the International Agency for Research on Cancer (IARC) and by the U.S. Department of Health and Human Services . These state that "Asbestos exposure is associated with parenchymal asbestosis , asbestos-related pleural abnormalities, peritoneal mesothelioma , and lung cancer , and it may be associated with cancer at some extra- thoracic sites". In other scientific publications, epidemiologists have published peer-reviewed scientific papers establishing that chrysotile

116-680: A linear stress–strain relationship , as shown in figure 1 up to point 3. The elastic behavior of materials often extends into a non-linear region, represented in figure 1 by point 2 (the "yield strength"), up to which deformations are completely recoverable upon removal of the load; that is, a specimen loaded elastically in tension will elongate, but will return to its original shape and size when unloaded. Beyond this elastic region, for ductile materials, such as steel, deformations are plastic . A plastically deformed specimen does not completely return to its original size and shape when unloaded. For many applications, plastic deformation

145-403: A material is an intensive property ; therefore its value does not depend on the size of the test specimen. However, depending on the material, it may be dependent on other factors, such as the preparation of the specimen, the presence or otherwise of surface defects, and the temperature of the test environment and material. Some materials break very sharply, without plastic deformation , in what

174-500: A silicate mineral of aluminium and fluorine Chrysoberyl , an aluminate of beryllium Zircon , a mineral belonging to the group of nesosilicates Prehnite , an inosilicate of calcium and aluminium Tourmaline , a crystalline boron silicate mineral compounded with other elements Apatite , a group of phosphate minerals See also [ edit ] List of gemstones in the Bible § Chrysolite Topics referred to by

203-424: Is Mg 3 ( Si 2 O 5 )( OH ) 4 , although some of the magnesium ions may be replaced by iron or other cations . Substitution of the hydroxide ions for fluoride , oxide or chloride is also known, but rarer. A related, but much rarer, mineral is pecoraite , in which all the magnesium cations of chrysotile are substituted by nickel cations. Chrysotile is resistant to even strong bases (asbestos

232-408: Is because the engineering stress is calculated assuming the original cross-sectional area before necking. The reversal point is the maximum stress on the engineering stress–strain curve, and the engineering stress coordinate of this point is the ultimate tensile strength, given by point 1. Ultimate tensile strength is not used in the design of ductile static members because design practices dictate

261-493: Is called a brittle failure. Others, which are more ductile, including most metals, experience some plastic deformation and possibly necking before fracture. Tensile strength is defined as a stress, which is measured as force per unit area. For some non-homogeneous materials (or for assembled components) it can be reported just as a force or as a force per unit width. In the International System of Units (SI),

290-422: Is different from Wikidata All article disambiguation pages All disambiguation pages Chrysotile Three polytypes of chrysotile are known. These are very difficult to distinguish in hand specimens, and polarized light microscopy must normally be used. Some older publications refer to chrysotile as a group of minerals—the three polytypes listed below, and sometimes pecoraite as well—but

319-484: Is the main cause of pleural mesothelioma . Chrysotile has been recommended for inclusion in the Rotterdam Convention on Prior Informed Consent , an international treaty that restricts the global trade in hazardous materials. If listed, exports of chrysotile would only be permitted to countries that explicitly consent to imports. Canada , a major producer of the mineral, has been harshly criticized by

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348-421: Is the maximum stress that a material can withstand while being stretched or pulled before breaking. In brittle materials, the ultimate tensile strength is close to the yield point , whereas in ductile materials, the ultimate tensile strength can be higher. The ultimate tensile strength is usually found by performing a tensile test and recording the engineering stress versus strain . The highest point of

377-473: Is thus stable in high pH pore water of Portland cement ), but when the fibres are attacked by acids, the magnesium ions are selectively dissolved, leaving a silica skeleton. It is thermally stable up to around 550 °C (1,022 °F), at which temperature it starts to dehydrate . Dehydration is complete at about 750 °C (1,380 °F), with the final products being forsterite (magnesium silicate), silica and water. The global mass balance reaction of

406-459: Is unacceptable, and is used as the design limitation. After the yield point, ductile metals undergo a period of strain hardening, in which the stress increases again with increasing strain, and they begin to neck , as the cross-sectional area of the specimen decreases due to plastic flow. In a sufficiently ductile material, when necking becomes substantial, it causes a reversal of the engineering stress–strain curve (curve A, figure 2); this

435-534: The Canadian Medical Association for its opposition to including chrysotile in the convention. According to EU Regulation 1907/2006 ( REACH ) the marketing and use of chrysotile, and of products containing chrysotile, are prohibited. As of March 2024, the U.S. Environmental Protection Agency finalized regulations banning imports of chrysotile asbestos (effective immediately) due to its link to lung cancer and mesothelioma . However,

464-688: The WTO and the European Commission concerning France's 1996 prohibition of the importation and sale of all forms of asbestos. Canada said that the French measures contravened provisions of the Agreements on Sanitary and Phytosanitary Measures and on Technical Barriers to Trade, and the GATT 1994. The EC claimed that safer substitute materials existed to take the place of asbestos. It stressed that

493-472: The stress–strain curve is the ultimate tensile strength and has units of stress. The equivalent point for the case of compression, instead of tension, is called the compressive strength . Tensile strengths are rarely of any consequence in the design of ductile members, but they are important with brittle members. They are tabulated for common materials such as alloys , composite materials , ceramics , plastics, and wood. The ultimate tensile strength of

522-523: The 2006 recommendations of the International Mineralogical Association prefer to treat it as a single mineral with a certain variation in its naturally occurring forms. Clinochrysotile is the most common of the three forms, found notably at Val-des-Sources, Quebec , Canada . Its two measurable refractive indices tend to be lower than those of the other two forms. The orthorhombic paratypes may be distinguished by

551-500: The French measures were not discriminatory under the terms of international trade treaties, and were fully justified for public health reasons. The EC further claimed that in the July consultations, it had tried to convince Canada that the measures were justified, and that just as Canada broke off consultations, it (the EC) was in the process of submitting substantial scientific data in favour of

580-478: The asbestos ban. In the late 1990s and early 2000s, the Government of Canada continued to claim that chrysotile was much less dangerous than other types of asbestos. Chrysotile continued to be used in new construction across Canada, in ways that are very similar to those for which chrysotile was exported. Similarly, Natural Resources Canada once stated that chrysotile, one of the fibres that make up asbestos,

609-521: The chrysotile dehydration can be written as follows: The chrysotile (serpentine) dehydration reaction corresponds to the reverse of the forsterite (Mg- olivine ) hydrolysis in the presence of dissolved silica ( silicic acid ). Previously, in the 1990s it was used in asbestos-cement products (like pipes and sheets). Magnesium sulfate (MgSO 4 ) may be produced by treating chrysotile with sulfuric acid (H 2 SO 4 ). Chrysotile has been included with other forms of asbestos in being classified as

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638-626: The fact that, for orthochrysotile, the higher of the two observable refractive indices is measured parallel to the long axis of the fibres (as for clinochrysotile); whereas for parachrysotile the higher refractive index is measured perpendicular to the long axis of the fibres. Bulk chrysotile has a hardness similar to a human fingernail and is easily crumbled to fibrous strands composed of smaller bundles of fibrils. Naturally-occurring fibre bundles range in length from several millimetres to more than ten centimetres, although industrially-processed chrysotile usually has shorter fibre bundles. The diameter of

667-412: The fibre bundles is 0.1–1  μm , and the individual fibrils are even finer, 0.02–0.03 μm, each fibre bundle containing tens or hundreds of fibrils. Chrysotile fibres have considerable tensile strength , and may be spun into thread and woven into cloth. They are also resistant to heat and are excellent thermal, electrical and acoustic insulators. The idealized chemical formula of chrysotile

696-592: The new rules can allow up to a dozen years to phase out the use of chrysotile asbestos in some manufacturing facilities. The long phase-out period was a result of a strong lobby by Olin Corporation , a major chemical manufacturer, as well as trade groups like the U.S. Chamber of Commerce and the American Chemistry Council . Chrysotile asbestos is now banned in more than 50 other countries. In May 1998, Canada requested consultations before

725-417: The same term [REDACTED] This disambiguation page lists articles associated with the title Chrysolite . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Chrysolite&oldid=1251905415 " Category : Disambiguation pages Hidden categories: Short description

754-584: The unit is the pascal (Pa) (or a multiple thereof, often megapascals (MPa), using the SI prefix mega ); or, equivalently to pascals, newtons per square metre (N/m ). A United States customary unit is pounds per square inch (lb/in or psi). Kilopounds per square inch (ksi, or sometimes kpsi) is equal to 1000 psi, and is commonly used in the United States, when measuring tensile strengths. Many materials can display linear elastic behavior , defined by

783-450: The use of the yield stress . It is, however, used for quality control, because of the ease of testing. It is also used to roughly determine material types for unknown samples. The ultimate tensile strength is a common engineering parameter to design members made of brittle material because such materials have no yield point . Typically, the testing involves taking a small sample with a fixed cross-sectional area, and then pulling it with

812-1280: The workplace. However, under increasing criticism by environmental groups, in May, 2012, the Canadian government stopped funding the Chrysotile Institute. As a result, the Chrysotile Institute has now closed. The Canadian government continues to draw both domestic and international criticism for its stance on chrysotile, most recently in international meetings about the Rotterdam Convention hearings regarding chrysotile. The CFMEU pointed out that most exports go to developing countries. Canada has pressured countries, including Chile , and other UN member states to avoid chrysotile bans. In September 2012, governments in Quebec and Canada ended official support for Canada's last asbestos mine in Asbestos, Quebec , now renamed as Val-des-Sources . Tensile strength Ultimate tensile strength (also called UTS , tensile strength , TS , ultimate strength or F tu {\displaystyle F_{\text{tu}}} in notation)

841-438: Was not as dangerous as once thought. According to a fact sheet from 2003, "current knowledge and modern technology can successfully control the potential for health and environmental harm posed by chrysotile". The Chrysotile Institute, an association partially funded by the Canadian government, also prominently asserted that the use of chrysotile did not pose an environmental problem and the inherent risks in its use were limited to

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