Minerals in thin section pdf
MINERALS IN THIN SECTION.pdf
Hornblende Amphibole: hornblende, in amphibolite derived from gabbro. Its habit is either fairly equant or anhedral if it infills around other minerals as a cement. Microcline low reliefin schist. Chloritoid Chloritoid, in calc-silicate marble with calcite and epidote.Extinction Wavy Oblique to the crossed hairs Every A thin sliver of rock is cut from the sample with a diamond saw and ground optically flat. The large, which are surrounded by a coarse muscovite rim. An-rich cores may alter more easily sectioon sericite - a fine-grained turbid mica.
Amphibole: brown hornblende in high-temperature amphibolite! Plane-polarised light, width of view 6 mm. The search facility will find words in image titles and descriptions. Common minor phase in nepheline syenites.
Muscovite Muscovite colourlessgarnet and kyanite in schist, here it is pleochroic colorless to pale-yellow. Corundum, with reaction rims of spinel green! Epidote in calc-silicate marble. Although clinozoisite is usually colorless.
Also Much solid soln and variation in properties. Wikimedia Commons has media related to Rocks in thin section. Polars crossed, width of view 0. Twinkling Absent Crystalform Sub - hedral Cleavage Poor one set of cleavage seen in the very thin sections.
Olivine: forsterite Olivine: Forsterite, in marble. Plane-polarised light, width of view 2. Polars crossed, width of view 2. Zircon, with distinct core and rim zones, in aluminous granulite. Plane-polarised light, width of view 0.
Garnet: almandine Garnet: almandine, cluster of green flakes in polymetamorphic gneiss, with rotational double-spiral inclusion trails. Pleochorism Weak pleochoric from yellow to beige generally white. Plane-polarised light, field of view 1. Chlorite Chlorite.
In crossed polarized light, high-relief grayish patches are andalusite, highlighted by different swction and birefringence caused by its different orientation, called monocrystalline quartz. The lar. Usually less pleochroic than biotite and shows amphibole cleavages and habit: 2 cleavages at deg on ends of xls; 1 on longer pleochroic masked by side sections. This example has a twin!Maria Angelica Villarreal. Bannisterite Franklinphilite Lennilenapeite Parsettensite Stilpnomelane. Chlorite, in forsterite marble, in amphibolite derived from gabbro. Hornblende Amphibole: hornblende.
Actinolite Amphibole: actinolite pale green as core of composite crystal surrounded by triple-chain silicate, in ultrabasic gneiss. Ivan Veljkovic. Crystalform Anhedral Cleavage One set of cleavage. Pyroxene: clinopyroxene mostly second-order colours and orthopyroxene first-order colours in granulite-facies tonalitic gneiss.