Thin Section Description Of Granite

Biotite brown grains in plain light and pinkish brown with crossed polars the brown color is due to a property called.

Thin section description of granite.

The second is a thin section rock description where you have a slice of the rock which is on a glass slide making it possible to view the rock under a microscope. To link to this object paste this link in email im or document to embed this object paste this html in website. The mineralogy of this granite is relatively simple biotite quartz and two feldspars plagioclase and k feldspar. This sample is a less evolved portion of the intrusion which was associated with the tourmaline and topaz rich intrusions and mineralisation.

Biotite metaluminous granite showing a close up of one crystal. These are photographs of a thin section of granite magnification 10x perhaps the most common igneous rock we encounter. Granite ˈ ɡ r æ n ɪ t is a common type of felsic intrusive igneous rock that is granular and phaneritic in texture. The large pink carlsbad twinned k feldspar megacrysts dominate the thin section.

Strictly speaking granite is an. The thin section illustrates the quartz rich nature of the rock which. By comparing the plane polarized light left and crossed polarizer right images we can see that there are three minerals in this granite. The classification of rocks is based on the information acquired during the petrographic analysis petrographic descriptions start with the field notes at the.

Hand specimen descriptions focus on physical properties of the rocks whereas the thin section descriptions looks at optical properties instead. Fluorapatite ilmenite and titanite are also present in minor amounts. Petrography is a branch of petrology that focuses on detailed descriptions of rocks someone who studies petrography is called a petrographer the mineral content and the textural relationships within the rock are described in detail. Granites can be predominantly white pink or gray in color depending on their mineralogy the word granite comes from the latin granum a grain in reference to the coarse grained structure of such a completely crystalline rock.

Damage produced during thin section grinding causes speckles of light in the biotite where the crystal lattice has been deformed.