Adopt-a-Mineral Project
Shawn Russell

www.emporia.edu/earthsci/amber/go336/russell

This webpage project was created for a mineralogy course at Emporia State University. The assigment was to learn webpage creation and present a summary of the minerals muscovite and kyanite.

Table of Contents
  • Introduction
  • Muscovite
    		•
  • Kyanite
  • Conclusion
    		•
  • Sources
  • Related links

    • Introduction

    Mineralogy is a subfield of the geosciences that includes crystallography and mineral genesis, as well as the physical, chemical, and optical properties of naturally occurring, crystalline solids (S. Aber, pers. comm. 8/2007). Definitions of mineral include the following points: naturally occurring, homogeneous solid, inorganic origin, definite chemical composition, and characteristic atomic structure.

    Muscovite

    Muscovite, KAl3Si3O10(OH)2, is a basic potassium aluminum silicate and part of the phyllosilicates subclass (Chesterman, p. 531). Muscovite ia part of the mica group and is the most common mica. Muscovite can be found in granite, pegmatite, gneiss, and schist (Wikipeda.org).

    The color of muscovite can be a yellowish, but also greenish, pink, or multicolored. Muscovite has a vitreous luster and a streak that is colorless. On the Mohs hardness scale muscovite is 2-2.5, and has perfect one-directional cleavage. It is classifed in the monoclinic crystal system and has a specific gravity of 2.7 to 3.0 (Chesterman, p. 531).

    When observing muscovite on end it resembles pages of a book, which is a reflection of the one-directional cleavage. The pages peal off one layer at a time creating thinner and thinner elastic sheets. The name is from a popular name muscovy glass, which refers to its use as a window glass substitute in Russia. Muscovite is still used as windows in gas stoves because it can withstand high temperatures (Chesterman, p. 532). Muscovite is also in demand for the manufacturing of fireproofing and insulation materials (Wenk & Bulakh).

    Images of muscovite are shown below. The center image is muscovite in thin section and shown through the microscope under cross polarized lenses, which is responsible for the bright unnatural color.



    Taken from University of Texas,
    www.utexas.edu/tmm/
    npl/mineralogy/index.htm    ,
    Gem and Mineral Collection
    www.utexas.edu/tmm/npl/
    mineralogy/Blowups/Muscovite.htm
    Image taken from University of
    North Carolina at Chapel Hill,
    www.geosci.unc.edu/Petunia/
    IgMetAtlas/minerals/muscovite.X.html
    Atlas of Igneous and Metamorphic Rocks,
    Minerals, and Textures.
    www.geolab.unc.edu/Petunia/
    IgMetAtlas/mainmenu.html
    Image taken from
    Gem and Mineral Miners, Inc.
    www.mineralminers.com/
    html/musmins.stm

    Kyanite

    Kyanite [(Al2SiO5)] is an aluminum silicate and belongs to a subclass of the silicates called nesosilicates (Chesterman p.579). Forming in a lower temperature and higher pressure environment kyanite is found in metamorphic rocks (Powell,1998). Kyanite is a polymorph with andalusite and sillimanite.

    Kyanite can be blue, white, colorless, gray, green, and nearly black. The streak of kyanite is colorless and it displays a vitreous luster (Chesterman p.579). Kyanit has a unique property in the fact that it is anisotropic and has a hardness of 4.5 to 5 lengthwise and 6.5 to 7 crosswise (Wikipedia.org).

    Image taken from Aelwyn at
    en.wikipedia.org/wiki/
    Image:Kyanite_crystals.jpg

    Kyanite has perfect one direction lengthwise cleavage and good second directional cleavage. While it displays cleavage, kyanite has a splintery fracture as well. A high specific gravity og 3.5 to 3.7.Belonging to the triclinic crystal system and forming in a bladed habit.(Chesterman p.579).

    Conclusion

    Muscovite can withstand high temperatures and it is one of the easier minerals to identify. Muscovite is light in color, has a vitreous luster, and is found primarily in igneous and metamorphic rock.
    Kyanite is used in ceramic products and dinnerware, can be used in electrical insulators and as an abrasive. With it's buetiful color kyanite is sometimes used as a gemstone. If not for it's varying hardnessand perfect cleavage I belive it would be one of the more popular gemstones due to it's beauty.

    Sources

  • Chesterman, C. W. 2006. National Audubon society field guide to North American rocks and minerals. Alfred A. Knopf: NY.
  • Powell, Darell. 1998. Kyanite. WWW URL: www.mii.org/Minerals/photokyanite.html. Retrieved October 15, 2007
  • Wenk, R. & Bulakh, A. 2004. Minerals their constitution and origin. Cambridge University Press.
  • Wikipedia 2007. Muscovite. WWW URL: en.wikipedia.org/wiki/Muscovite. Retrieved September 5, 2007.
  • Wikipedia 2007. Kyanite. WWW URL: en.wikipedia.org/wiki/Kyanite. Retrieved October 15, 2007. .

    Related Links
    Emporia State University
    www.emporia.edu     		Earth Science at ESU
    www.emporia.edu/earthsci
    Mineralogy Webpage Assignment
    www.emporia.edu/earthsci/amber/
    go336/assign.htm         		Mineralogy Student Webpages
    www.emporia.edu/earthsci/amber/
    go336/webpages.htm

    For more information email Shawn at srussell@emporia.edu.

    Return to GO 336 Student webpages, www.emporia.edu/earthsci/amber/go336/webpages.htm. Latest update 27 November 2007.