Petrography of Igneous and Metamorphic
Rocks
This web site includes over 200 photomicrographs of igneous and metamorphic
rocks and their minerals. All photographs are of thin sections of rocks
ground to .03 mm thickness, in transmitted white light. Some show the appearance
of minerals in plane polarized light, but most were taken with crossed polarizers
using a petrographic microscope, better to illustrate mineral colors and
textures. The majority of the pictures were made at 80X magnification; other
magnifications are indicated where different.
This collection is intended as an instructional tutorial for students of
geology who are somewhat familiar with mineral optics, but many people may
find the beauty of minerals in polarized light sufficient reason to browse
this site.
The photographs are arranged to illustrate common igneous
minerals, metamorphic minerals,
rocks that are formed from these minerals, and some common rock textures.
I suggest that you begin by looking at the minerals.
Home Minerals
List Rocks List