71840 Quartz diorite - Virtual Microscope
This collection of virtual thin sections is the result of a collaboration between earth scientists at Leicester University and The Open University. The collection consists of 135 slides from the Leicester teaching collection, including igneous, metamorphic and sedimentary rocks.
Quartz thin section - Tectosilicates - MicROCKScopic
Quartz thin section photomicrographs are taken in plane-polarized light and cross-polarized light, and can easily be recognized under the microscope.
Diorite - ALEX STREKEISEN
Diorite is a coarse-grained, intrusive igneous rock that is intermediate in composition between granite and gabbro. Diorite is composed primarily of plagioclase feldspar, amphibole, and pyroxine minerals with small amounts of biotite mica. It typically contains very little quartz.
16 Photo Gallery of Rocks in Hand Specimen and Thin Section
The thin-section view shows large crystals of blocky sanidine (some with Carlsbad twinning), plagioclase (with albite twins), and (untwinned) quartz in a fine matrix of feldspar, quartz, and glass. Minor magnetite is also present in the groundmass.
Prepare a labelled sketch of each selected thin section, being sure to label the sketch with magnification and either CN or PP. Identify the major minerals, and write a concise description of the petrography of the rock.
Diorite – Loch Doon - Virtual Microscope
In thin section this diorite contains laths of plagioclase feldspar often 2-3 millimetres long, and minor amounts of quartz. The mafic minerals are dominated by high relief pyroxene with it's characteristic cleavage, and common biotite which exhibits some pleochroic haloes caused by zircon inclusions.
a Thin section of potassic alteration and silicified vein in diorite ...
Download scientific diagram | a Thin section of potassic alteration and silicified vein in diorite with opaque minerals (Op), plagioclase (Pl), quartz (Qtz), and XPL (cross-polarized...
Quartz diorite - Wikipedia
Quartz diorite is an igneous, plutonic rock, of felsic composition, with phaneritic texture. Feldspar is present as plagioclase (typically oligoclase or andesine ) with 10% or less potassium feldspar.
Diorite: Composition, Properties, Occurrence, Uses - Geology In
Geologists employ the modal abundance (percentage by volume) of key minerals to classify diorite: Quartz Diorite: When quartz content surpasses 5% but remains less than 20%, the rock is classified as quartz diorite. This additional quartz imparts a …
MYRMEKITE 43 of 50 - California State University, Northridge
A sequence of sixteen photomicrographs of thin sections of unaltered quartz diorite through a zone of deformation to myrmekite-bearing granite near Temecula, California, shows the textural and mineralogical changes that occurred in a quartz diorite as (1) K-metasomatism altered the primary plagioclase crystals to form microcline, myrmekite ...