Mica minerals

Moisture Deteriorating effects of moisture are well known as reviewed early in this chapter (OTHER BEHAVIOR, Drying Plastic). Examples for high moisture applications include polyphenylene oxide, polysulfone, acrylic, butyrate, diallyl phthalate, glass-bonded mica, mineral-filled phenolic, chlorotrifluoroethylene, vinylidene, chlorinated polyether chloride, vinylidene fluoride, and fluorocarbon. Diallyl phthalate, polysulfone, and polyphenylene oxide have performed well with moisture/steam on one side and air on the other (a troublesome... 

Mica Mineral wool fibre 3 (respirable dust) 10 " ... 

A group of mica miners were said to show a higher incidence of pneumoconiosis than miners of other minerals, but some quartz was present in the dust to which they were all exposed. ... 

Figure 4 SEM images of a kaolinite-quartz-mica mineral mix after flocculation by HPAM. The kaolin covers other minerals encapsulating them inside the floes...

There is, therefore, a difference between the true mica minerals... 

The dominant class of nacreous pigments is based on platelets of natural mica coated with thin films of transparent metal oxides (see Fig. 73). Mica minerals are sheet silicates (laminar). Nacreous pigments are usually based on transparent muscovite [9941-63-5] but some are based on natural or synthetic phlogopite [110710-26-4]. Although muscovite occurs worldwide, few deposits are suitable for pigments it is biologically inert and approved for use as a filler and colorant [5.220], [5.221],... 

Elements with ionic species commonly associated with quartz and mica minerals such as Na, Zr, and Hf are more likely to co-vary with those minerals rather than hematite. The ratio of these latter elements to Fe-substituting elements would be dependent on the relative amounts of hematite and other minerals in the sample rather than just die rock-forming processes. For this reason, elements that commonly substitute into quartz and other abundant minerals in the samples were excluded from the discriminant analysis. Some rare earth elements may also play a role in fingeiprinting the sources, and their importance was tested by comparing discriminant analysis models with and without La, Sm, and Th. 

Glauconite is also a mica mineral with a large part of the octahedral A1 replaced by Fe(III). An average composition (14) is... 

Brindley, G.W., 1956. Allevardite, a swelling double layer mica mineral. Am. Mineralogist, 41 91 — 103. 

Grum-Grzhimailo, S. V., Anikina, L. I., Belova, E. N. Tolstikhina, K. I. (1955) Curves of spectral absorption and other physical constants of natural micas. Mineral. Sbomik. Lvov Geol. Obshch., 9, 90-119. 

Robbins, D. W. Strens, R. G. J. (1972) Charge transfer ferromagnesian silicates The polarized electronic spectra of trioctahedral micas. Mineral Mag., 38 551-63. 

Rath, R.K. and S. Subramanian, Studies on adsorption of guar gum onto biotite mica, Miner. Eng., 10, 1405, 1997. 

Although compounds of sodium and potassium were known in ancient times, it was not until Humphrey Davy s famous electrolytic experiments in 1807 on molten caustic soda and potash that the metals themselves were first isolated. Lithium was first recognized as an alkali metal in various silicate and mica minerals in 1817 (by ArfVedson, who thus named it from the Greek word for stone) and first isolated, again by Davy, in 1818. The discovery of cesium (1860) and rubidium (1861) had to await the development of atomic spectroscopy (by Bunsen and Kirchoff) their names reflect the colors of their dominant spectral lines (Latin caesius, sky blue, and rubidus, deep-red). 

The reactions of several other minerals which thermally decompose to form mullite have been studied by Si and Al NMR. These include the mica mineral muscovite, which also contained sufficient iron to permit a complementary Fe Mossbauer study (MacKenzie et al. 1987), the hydroxyfluoride mineral topaz (Day et al. 1995) and the semi-amorphous aluminosilicate minerals allophane (MacKenzie et al. 1991) and imogolite (MacKenzie et al. 1989). The same combination of NMR nuclei has been used to study the thermal decomposition of other aluminosilicates including an illite-rich clay (Roch et al. 1998), montmorillonite (Brown et al. 1987), and a related mineral, Fuller s Earth (Drachman et al. 1997). NMR has also been used to study the effect of water vapour on the thermal decomposition of montmorillonite clay compacts (Temuujin et al. 2000a). 

Biotite. A member of the mica mineral group lustrous, with a dark green, brown to black color approximate composition K(Mg,Fe)3(Al-SijO.oKOH) . 

Know the basic structures of the major clay and mica mineral groups and the definitions of octahedral, dioctahedral, gibbsite, brucite, and tetrahedral layers. 

Higashi S (1982) Tobelite, a new ammonium dioctahedral mica. Mineral J 11 138-146 Hirschmaim M, Evans BV, Yang H (1994) Composition and temperature dependence of Fe-Mg ordering in cummingtonite-granerite as determined by X-ray diffraction. Am Mineral 79 862-877 Hoppe R (1979) Effective coordination numbers (ECON) and mean fictive ionic radii (MEFIR). Z Kristallogr 150 23-52... 

Kato T, Mima Y, Yoshii M, Maeda K (1979) The crystal stracture of IM-kinoshitalite, a new barium brittle mica and IM-manganese trioctahedral micas. Mineral J 9 392-408 Keppler H (1990) Ion exchange reactions between dehydroxylated micas and salt melts and the crystal chemistry of the interlayer cations in micas. Am Mineral 75 529-538 Keusen HR, Peters T (1980) Preiswerkite, an Al-rich trioctahedral sodium mica from the Geisspfad ultramafic complex (Penninic Alps). Am Mineral 65 1134-1137 Knurr RA, Bailey SW (1986) Refinement of Mn-substituted muscovite and phlogopite. Clays Clay Minerals 34 7-16... 

Tepikin EV, Drits VA, Alexandrova VA (1969) Crystal stractrrre of iron biotite and corrstraction of structural models for trioctahedral micas. Proc 4th IntT Clay Conf, Tokyo, p 43-49 Tlili A, Smith DC, Beny J-M, Boyer H (1989) A Raman microprobe study of natrrral micas. Mineral Mag 53 165-179... 

Takeuchi Y, Haga N (1971) Structural transformation of trioctahedral sheet sihcates. Shp mechanism of octahedral sheets and polytypic changes of micas. Mineral Soc Japan Spec Paper 1 74-87 (Proc IMA-lAGOD Meetings 70, IMA Vol)... 

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