Enjoying Rocks Under the Microscope
"thin section" is made by gluing a rock chip to a glass slide and then
grinding the rock to a thickness less than paper. Under ordinary
light, the result is rather colorless, but when the slide is placed between
pieces of polarizing film, the interference of light rays produces results
which are both spectacular and diagnostic for specific minerals.
The purpose of this section is to invite the lay person or high school
student into the world of rocks under the polarizing light microscope (PLM).
Several images of a metamorphic rock known as "kyanite-muscovite-biotite-garnet
schist" can be viewed in the Photomicrograph
This page will guide you to the minerals you see in the gallery and
the properties by which they are identified. It concludes with links
to other sites that will continue your introduction to rocks under
Minerals and their properties
The minerals seen in the gallery slides include the following:
These minerals are distinguished by the following properties:
Additional properties are described in some of the references below.
Links to Other Sites
State U. Petrography tutorial
A systematic survey of minerals making up igneous, metamorphic, and sedimentary
under the Microscope
Very nice discussion and illustrations of the properties of minerals as
seen under the microscope. The down side: All the aspects are placed
on a single page which takes many minutes to receive (from Australia to
the U.S.) even on a fast internet connection.
Access to software and QuickTime files that allow you to see how a thin
section changes its appearance as it is rotated on the microscope stage.
Instructive, but you must download software and will need a fast internet
Smith thesis pictures
Pretty pictures from a thesis on high-grade metamorphic rocks, part of
an individual's web pages.
Rocks - Duke U.
A few typical igneous rocks both in hand specimen and thin section - from
a college course.