Changes

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file:M102Ch1Fg6.jpg|{{figure number|6}}(a) A BSE and CL image of a polished shale sample. Orange-hued quartz grains reflect low-grade metamorphic origin (slate); blue-hued quartz grains indicate higher grade metamorphism (phyllite-schist). (b) Detail of a large quartz grain in center of image (arrow) displays multiple generations of growth in CL; this distinction in zoning is not visible in SEM.<ref name=Huangetal_2013 />

file:M102Ch1Fg6.jpg|{{figure number|6}}(a) A BSE and CL image of a polished shale sample. Orange-hued [[quartz]] grains reflect low-grade metamorphic origin (slate); blue-hued quartz grains indicate higher grade metamorphism (phyllite-schist). (b) Detail of a large quartz grain in center of image (arrow) displays multiple generations of growth in CL; this distinction in zoning is not visible in SEM.<ref name=Huangetal_2013 />

file:M102Ch1Fg7.jpg|{{figure number|7}}An example of an x-ray spectrum acquired from a shale sample. Individual peaks indicate an elevated concentration of a given element. C=carbon, O=oxygen, Mg=magnesium, Al=aluminum, Si=silicon, Ca=calcium.<ref name=Huangetal_2013 />

file:M102Ch1Fg7.jpg|{{figure number|7}}An example of an x-ray spectrum acquired from a shale sample. Individual peaks indicate an elevated concentration of a given element. C=carbon, O=oxygen, Mg=magnesium, Al=aluminum, Si=silicon, Ca=calcium.<ref name=Huangetal_2013 />

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Another complimentary technique is the detection of CL, in which certain materials will emit photons in the form of visible light as a result of interactions between specimen electrons and primary beam electrons. [[:file:M102Ch1Fg6.jpg|Figure 6]] shows an example of the effects of CL on a shale sample. The image was acquired with a dedicated CL detector. Variations in CL emission caused by mineral impurities could indicate provenance of individual quartz grains. Cathodoluminescence can also be used to differentiate between generations of quartz growth that are not distinguishable in SEM due to identical mean atomic number.

Another complimentary technique is the detection of CL, in which certain materials will emit photons in the form of visible light as a result of interactions between specimen electrons and primary beam electrons. [[:file:M102Ch1Fg6.jpg|Figure 6]] shows an example of the effects of CL on a shale sample. The image was acquired with a dedicated CL detector. Variations in CL emission caused by mineral impurities could indicate provenance of individual [[quartz]] grains. Cathodoluminescence can also be used to differentiate between generations of quartz growth that are not distinguishable in SEM due to identical mean atomic number.

==X-ray microanalysis==

==X-ray microanalysis==

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file:Figure-8.jpg|{{figure number|8}}A secondary electron image of a shale sample with an EDS-derived mineral segmentation overlay. In the segmented region, blue = carbonate, green = clay minerals, yellow = quartz, pink = feldspar, white = pyrite, and gray = organic matter.<ref name=Huangetal_2013 />

file:Figure-8.jpg|{{figure number|8}}A secondary electron image of a shale sample with an EDS-derived mineral segmentation overlay. In the segmented region, blue = carbonate, green = clay minerals, yellow = [[quartz]], pink = feldspar, white = pyrite, and gray = organic matter.<ref name=Huangetal_2013 />

file:Figure-9.jpg|{{figure number|9}}At left, a schematic diagram of operation of an FIB-SEM system. The FIB sputters away a thin layer of the sample at a time, while the electron beam/detector system captures an image of each newly exposed surface. At right, a picture of a commercial FIB-SEM CrossBeam™ system, Auriga.<ref name=Huangetal_2013 />

file:Figure-9.jpg|{{figure number|9}}At left, a schematic diagram of operation of an FIB-SEM system. The FIB sputters away a thin layer of the sample at a time, while the electron beam/detector system captures an image of each newly exposed surface. At right, a picture of a commercial FIB-SEM CrossBeam™ system, Auriga.<ref name=Huangetal_2013 />

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