Mica plates are elastic whereas chlorite plates are flexible without bending back. Recognizing a mineral as a member of the chlorite group is usually easy. The general formula may be stated A 5-6 T 4 Z 18, where A = Al, Fe 2+, Fe 3+, Li, Mg, Mn, or Ni, while T = Al, Fe 3+, Si, or a combination of them, and Z = O and/or OH. Detailed optical, chemical, or x-ray analysis is usually required for positive identification. The plates are flexible, but not elastic like mica. Another environment of chlorite mineral formation is in oceanic crust descending into subduction zones. As a result, the individual chlorite minerals are poorly known. An older classification divided the chlorites into two subgroups: the orthochlorites and leptochlorites. Name: Chlorite is derived from a Greek word meaning green, in allusion to the common color of the mineral. (Mg,Fe)3(OH)6. "Chlorite" is the name of a group of common sheet silicate minerals that form during the early stages of metamorphism. The chlorite ion, or chlorine dioxide anion, is the halite with the chemical formula of ClO 2. Mg5Al2- Si3Oio(OH)8 is the formula for clinochlore. As a result, chlorite is not mined and processed for any specific use. Since it cannot be concentrated, it is not a commercial product. The composition and physical properties of chlorites vary as these ions substitute for one another in solid solution. Several other sub-varieties have been described. Maderanertal, in Uri, Switzerland, is famous for its shiny green Chlorite coatings on Quartz and Adularia. This makes them difficult to differentiate in hand specimen. Chlorite is so soft that it can be scratched by a finger nail. Chlorite: Chlorite from Quebec, Canada. Various shades of green; rarely yellow, red, or white. A chlorite (compound) is a compound that contains this group, with chlorine in the oxidation state of +3. The chlorites are often, but not always considered a subset of the larger silicate group, The clays. Except where otherwise noted, data are given for materials in their, https://en.wikipedia.org/w/index.php?title=Chlorite&oldid=964481812, Pages using collapsible list with both background and text-align in titlestyle, Articles containing unverified chemical infoboxes, Creative Commons Attribution-ShareAlike License, This page was last edited on 25 June 2020, at 19:12. Various shades of green. Chlorite is a general name for several minerals that are difficult to distinguish by ordinary methods. Here, amphiboles, pyroxenes, and micas are altered into chlorite. Its major use is as a coincidental constituient in crushed stone. Metamorphic rocks rich in chlorite might include phyllite and chlorite schist. Chlorite occurs naturally in a variety of locations and forms. The composition and physical properties of chlorites vary as these ions substitute for one another in solid solution. Chlorite is commonly found in igneous rocks as an alteration product of mafic minerals such as pyroxene, amphibole, and biotite. For example, chlorite is found naturally in certain parts of Wales in mineral schists. Within ultramafic rocks, metamorphism can also produce predominantly clinochlore chlorite in association with talc. The name "chlorite" is often used in classrooms and the field because the minerals are difficult or impossible to identify. This (Mg2+, Fe3+)(OH)6 unit is more commonly referred to as the brucite-like layer, due to its closer resemblance to the mineral brucite (Mg(OH)2). Although Chlorite is a fairly common mineral and found worldwide, localities producing material worthy of collections are surprisingly limited. Chlorites have a 2:1 sandwich structure (2:1 sandwich layer = tetrahedral-octahedral-tetrahedral = t-o-t...), this is often referred to as a talc layer.  It does not have physical properties that make it suited for a particular use, and it does not contain constituents that make it a target of mining. It is the diagnostic species of the zeolite facies and of lower greenschist facies. When found, chlorite is usually intimately intermixed with other minerals, and the cost of separation would be high. These are part of a greater family of other chlorine oxides. The best way to learn about minerals is to study with a collection of small specimens that you can handle, examine, and observe their properties. Chlorite that forms here is usually associated with biotite, muscovite, garnet, staurolite, andalusite, or cordierite. The free acid, chlorous acid HClO2, is the least stable oxoacid of chlorine and has only been observed as an aqueous solution at low concentrations.