Biotite mica

The aluminosilicates examined were chosen as end members of those groups of phyl losil icates that commonly occur in soils muscovite and biotite mica, Fithian and Morris illite, Montana vermicul ite, montmoril Ionites from Upton (Wyoming bentonite), Camp Berteau, Redhill and New Mexico, and kaolinites from St. Austell, England, and Georgia, U.S.A. 

Chakraborty, S., Wolthers, M., Chatterjee, D. and Charlet, L. (2007) Adsorption of arsenite and arsenate onto muscovite and biotite mica. Journal of Colloid and Interface Science, 309(2), 392-401. 

FIGURE 4. Photograph (a) and autoradiograph (b) of technetium sorbed on a biotite mica thin section. 

If the silica sheets in a 2 1 Fe-rich clay had enough A1 substitution to adjust to the size of the octahedral sheet, this would most likely provide sufficient layer charge to cause contraction and the formation of a biotite mica, or the bonding of a positively charged brucite sheet and the formation of a chlorite. Low-temperature micas of this composition may well exist, but have not yet been recognized. It is not known if low-temperature chlorites of this composition can form. 

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

Illite = similar to biotite mica, but less cation-rich Montmorillonite = (Na,Ca)(Al,Mg)6(Si40io)3(OH)6-nH20). 

Biotite mica Dark brown Flaky Much softer than Granite, gneiss... 

Micas lose their structural relatively rapidly by a process of cation exchange with or metal ions in the weathering solution. This initial reaction is an alteration that is not necessarily very sensitive to pH. The pH, however, tends to rise during alteration as H" is adsorbed. The secondary mineral formed directly is a vermiculite, which inherits more or less intact the 2 1 layer structure of the mica parent. An ideal biotite mica might have the formula ... 

Figure 6.5. The relation between the fraction of the initial K" remaining, Q/Qo, in biotite mica samples of different particle si2e and the time of reaction with a NaCl-Na tetraphenylboron solution. (Data from M. G. Reed and A. D. Scott. 1962. Kinetics of potassium release from biotite and muscovite in sodium tetraphenylboron solutions. Soil Sci. Soc. Am. Proc. 26 437-440.)...

Chandra R, Lokanathan S (1977) Electric field gradient in biotite mica. Phys Stat Solidi 83 273-280 Chandra U, Lokanathan S (1982) A Mossbauer study of the effect of heat treatment on biotite micas. J Phys D Appl Phys 15 2331-2340... 

Heavy silicate minerals, containing heavy elements such as iron, magnesium, calcium and aluminium. These heavy silicates are known as biotite mica, amphibole, pyroxenes, olivine and feldspar. 

Vermiculite. A group name for certain biotite micas that have been altered hydrothermally. When rapidly heated to 800-950°C vermiculite exfoliates as the combined water is expelled the volume increase is about 15%. Large deposits of vermiculite occur in USA, Transvaal, Uganda, Australia and the Ural Mountains of Russia. The exfoliated... 

The ease with which feldspar enters into solution during smelting depends upon its fineness 120-140 mesh material is common in the enamel industry. Potash spar almost always is used. Soda spars frequently cause fishscaling in enamels that are entirely satisfactory when made with potash. Such impurities as garnet, hornblende, tourmaline and biotite mica cannot be tolerated. They maintain their identity throughout smelting, rise to the surface of the milled enamel and appear as hlack or hrown specks in the finished product. Muscovite mica, a potassium-aluminum sUicate, on the other hand, readily enters into solution and, therefore, is not particularly harmful. 

H2O. A hydrated biotite mica that has undergone alteration by further hydration. It possesses the peculiar property of exfoliating from 16-20 times its original size on heating. 

AlSi)40io] (0H)2 4H2O, a type of hydrated biotite mica. Vermiculite expands at heating to 650-1,000 °C up to 18-25 times. Before expansion, the density is 2.4— 2.7 g/sm after expansion, the density is 0.15-0.3 g/sm. The blowup (thermal expansion) of vermiculite is usually performed in fluidized bed furnaces. The expanded vermiculite has a low thermal conductivity and is a good heat insulation material. 

Saksena, B. D., 1964. Infrared hydroxyl frequencies of muscovite, phlogopite, and biotite micas in relation to their structures. Trans. Faraday Soc. 60 1715. 

Samples of the chlorite are relatively stable to heat, but the C horizon samples tend to collapse at 500° (K saturated) to 12.8 A, 11.6 A, and 10.0 A. The authors suggest that evidence exists for the formation of chlorite from biotite mica. 

Infrared hydroxyl frequencies of muscovite, phlogopite and biotite micas in relation to... 

Wilkins, R. W. T., The hydroxyl-stretching region of the biotite mica spectrum. Mineral. Mag. 36 325. 

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