Albite-crystallization

Matthews A. (1980). Influences of kinetics and mechanism in metamorphism A study of albite crystallization. Geochim. Cosmochim. Acta, 44 387-402. 

Mellott N. P., Brantley S. L., and Pantano C. G. (2002) Topography of polished plates of albite crystal and glass during dissolution. In Water-Rock Interactions, Ore Deposits, and Environmental Geochemistry, A Tribute to David A. Crerar, vol. Spec. Pub. No. 7 (eds. R. Hellmann and S. Wood). The Geochemical Society, St. Louis, MO, pp. 83-96. 

The compound albite, Na20 A1203 6SiOz, melts congruently at 1118 3°C. For those compositions in the albite field with a Iiquidus of about 1040°C or less, albite crystallized in a few days at a temperature 50 to 75° below Iiquidus temperatures. To the left of the carnegieite-silica line, a rapid decrease in the viscosity of melts in the albite field occurs. As a result, it is possible to crystallize albite even at temperatures around 750°C. In the albite field toward the system albite-silica, crystallization of albite is very difficult. 

K. Takabatake, Vitrification of albite crystal and structure change of albite glass by shock-wave compression. Master thesis of Kanazawa Univ. (2000). 

Some minerals display anisotropy of Raman peak intensities, depending on the optical direction in which they are recorded (see also Chapter 9), Figure 2 shows the Raman spectra of an albite crystal in three different directions. It is obvious that, although the peak positions do not change, the intensities of some of the peaks are different. This may lead to misinterpretation when a stone is not accessible from all sides, so that only one of the directions can be analyzed. 

Figure 2 Raman spectrum of an albite crystal recorded in three different crystallographical directions perpendicular to each other (x, y, z). The directional recording of spectra shows anisotropy with respect to the peak heights, but not the peak positions.

Crystallization and Fusion in an Open System Diopside-Albite-Anorthite as an Example... 

Bowen N. L. and Schairer I F. (1938). Crystallization equilibrium in nepheline-albite-silica mixtures with fayalite. J. Geol, 46 397-411. 

The third and the most common type is complex phase transformations, including the following (i) some components in a phase combine to form a new phase (e.g., H2O exsolution from a magma to drive a volcanic eruption the precipitation of calcite from an aqueous solution, Ca + + COf calcite the condensation of corundum from solar nebular gas and the crystallization of olivine from a basaltic magma), (ii) one phase decomposes into several phases (e.g., spinodal decomposition, or albite jadeite + quartz), (iii) several phases combine into one phase (e.g., melting at the eutectic point, or jadeite +... 

Anorthite was named by Rose in 1823 from the Greek meaning oblique, referring to its triclinie crystallization. The physical properties are essentially the same us tor albite. except that the specific gravity of anorthite is somewhat greater. 2.74-2.76. Anorthite is characteristic of the basic igneous rocks such as gahbro and basalt. Anorthite is found in the lavas of Vesuvius and Monte Somma. Italy in Finland Japan and in the United Stales, in Sussex County. New Jersey. 

Feldspars are found in nature in the form of mixed crystals of the alkali feldspars orthoclase K[AlSi308], albite Na[AlSi308] and anorthite Ca[Al2Si208]. Unlimited formation of mixed crystals of the alkali feldspars is only possible at high temperatures. During cooling demixing occurs. Potassium feldspar and calcium feldspar are not miscible. 

Microcline, albite and labradorite were obtained from Ward s Canada Limited. Cleaved crystal fragments and 60 mesh-sized samples were ultrasonically cleaned prior to use. Powdered samples (particle size < 25 ym) were prepared by grinding in a tungsten carbide ball mill, wet-sieving and washing in water. 

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