Albite In Thin Section

Chromite is a spinel type mineral like magnetite and has an extensive solid solution in the magnetite composition direction.

Albite in thin section. Rock forming minerals of metamorphic rocks in thin section a work in progress. This twinning is the most characteristic identifying feature of plagioclase and makes its identification easy when present. Cr mg al rich chromites are realtively transparent and can be dark brown at full thin section thickness.

Clinopyroxenes and orthopyroxenes are easily distinguished in thin section by their extinction angles. A bijoux google search for albite adam s minerals google search for. Calcite thin section photomicrographs are taken in plane polarized light and cross polarized light and can easily be recognized under the microscope.

Polars crossed field of view 2 5 mm. Albite is the sodic end member of both the plagioclase feldspar series and the alkali feldspar series. Colorless frequently cloudy due to incipient alteration pleochroism.

Chromite is dark brown to opaque at full thin section thickness. Clinopyroxenes have inclined extinction and orthopyroxenes have parallel extinction. Chemically jadeite lies intermediate between albite na alsi 3 o 2 and nepheline na alsi o 4.

Jadeite appears only in metamorphic rocks and is most common as a monomineralic rock. Low moderate negative positive albite anorthite series habit form. In thin section plagioclase commonly shows the characteristic albite polysynthetic twinning.

24 ucla petrography thin sections 25 www mincryst. Some specimens of labradorite exhibit a schiller effect which is a strong play of iridescent blue green red orange and yellow colors when moved under a source of incident light. If you have trouble remembering the name of the white feldspar and you re at all familiar with harry potter think of albus dumbledore whose first name albus is latin for white it s helped a surprising number of people keep their feldspars straight.