P number: | P524363 |
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Caption: | Photomicrograph of muscovite pegmatite. Light: XPL, Magnification x 2. Lochailort, Lochaber, Invernessshire. |
Description: | The image is a photomicrograph of a thin section of muscovite pegmatite. The bright colours are caused by the crossed-polarized light of the petrological microscope on which the image was taken. British Geological Survey Petrology Collection sample number LAP 1. Light: XPL, Magnification x 2. Light: XPL, Magnification x 2. The very bright colour is caused by muscovite. Like all mica minerals, it typically forms elongate laths, with a single cleavage forming striations parallel to the length of the crystals. Quartz and feldspar in the image show a variety of grey shades ranging from white to black. They have a more granular shape compared to the muscovite. This rock comes from an infold of the Glenfinnan Group of the Moine Supergroup, adjacent to a major ductile fault structure called the Sgurr Beag Slide. In the Lochailort area this structure brings higher-grade metamorphic rocks of the Glenfinnan group into contact with slightly lower-grade metamorphic rocks of the Morar Group. |
Date taken: | Wed Jan 01 00:00:00 GMT 2003 |
Photographer: | Hyslop, E.K. |
Copyright statement: | NERC |
Orientation: | Landscape |
Size: | 260.70 KB; 1000 x 667 pixels; 85 x 56 mm (print at 300 DPI); 265 x 176 mm (screen at 96 DPI); |
Average Rating: | Not yet rated |
Categories: | Best of BGS Images/ Rocks and minerals under the microscope |
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