This resource is a basic introduction to looking at rocks in thin section. The resource includes a section outlining the parts of a polarising light microscope. There is a section showing how this microscope can be used to study the optical properties of minerals in rock thin section. There are video clips showing the optical properties of minerals in six rock thin sections. The thin sections, covering a range of igneous, metamorphic and sedimentary rocks, were chosen to show the diagnostic properties of 10 of the main rock-forming minerals as seen under a polarising light microscope.
Polarising light microscope (2.38 MB)
This PowerPoint shows the main parts of the type of microscope used to study minerals in rock thin sections.
Minerals in thin section (8.84 MB)
This outlines the optical properties of minerals observed using a polarising light microscope.
Thin section 1
This video shows a thin section of a rock made of quartz, feldspar and lithic grains. The properties of the main rock-forming minerals as seen under a polarising light microscope are described. Images in this resource could be used to practise microscope drawing skills.
Thin section 2
This video shows a thin section of a rock made of quartz, feldspar biotite mica and muscovite mica. The properties of the main rock-forming minerals as seen under a polarising light microscope are described. Images in this resource could be used to practise microscope drawing skills.
Thin section 3
This video shows a thin section of a rock made of feldspar, olivine and pyroxene. The properties of the main rock-forming minerals as seen under a polarising light microscope are described. Images in this resource could be used to practise microscope drawing skills.
Thin section 4
This video shows a thin section of a rock made of quartz, muscovite mica, biotite mica and garnet. The properties of the main rock-forming minerals as seen under a polarising light microscope are described. Images in this resource could be used to practise microscope drawing skills.
Thin section 5
This video shows a thin section of a rock made of calcite and which is largely composed of skeletal grains (bioclasts). The properties of the main rock-forming minerals as seen under a polarising light microscope are described. Images in this resource could be used to practise microscope drawing skills.
Thin section 6
This video shows a thin section of a rock made of calcite and which is largely composed of non-skeletal grains. The properties of the main rock-forming minerals as seen under a polarising light microscope are described. Images in this resource could be used to practise microscope drawing skills.