Biotite In Thin Section

Biotite in thin section thin section gigapans.

Biotite in thin section. Biotite thin section photomicrographs are taken in plane polarized light and cross polarized light and can easily be recognized under the microscope. Home rocks and minerals biotite thin section reference url share. Biotite a different biotite another different biotite scanning electron micrograph of biotite from the tioga bentonite in seven fountains va.

Biotite usually dark green brown or black has a pale brown color under plane polarized light in this sample. Note the presence of the one perfect cleavage on the c axis parallel section and its absence on the basal section. Biotite k mg fe 2 3 alsi 3 o 10 oh f 2 biotite is a common phyllosilicate mineral within the mica group with the approximate chemical formula k mg fe 3 alsi 3 o 10 f oh 2 biotite is a solid solution between the end members phlogopite kmg 3 alsi 3 o 10 oh 2 and annite kfe 3 alsi 3 o 10 oh 2 although pure annite does not occur in nature in addition small amounts of na rb cs.

Crystals of biotite showing colour variation by pleochroism. Biotite is a solid solution between the end members phlogopite kmg 3 alsi 3 o 10 oh 2 and annite kfe 3 alsi 3 o 10 oh 2 although pure annite does not occur in nature. Biotite thin section view description.

Metamorphic reactions developed thin corona reaction assemblages between fe ti oxides and plagioclase biotite hornblende augite and garnet and between igneous augite and plagioclase hornblende. In thin section biotite exhibits moderate relief and a pale to deep greenish brown or brown color with moderate to strong pleochroism. C axis parallel section left and subhedral basal section right of brown biotite.

It is seen now in plane polarized light as a brown to tan color. Biotite is a common phyllosilicate mineral within the mica group. Add tags comment rate.

Biotite in biotite gneiss plane polars biotite in biotite gneiss crossed polars biotite in biotite granite plane polars. Small 250x250 max medium 500x500 max. Under cross polarized light the biotite thin section appears darker brown in areas as well as a pink yellow color in others.