Polarizing Microscope Colors

Minerals a rocks produce amazing colors. Using a polarizing microscope, Dr. Parvinder Sethi, Professor of Geology at Radford University captured these images of paper-thin slices of rocks with a 35mm film camera.

To prepare the rocks, Dr. Sethi used an industrial rock saw to cut a hand-sized piece of rock, then he trimmed it with an oil-cooled saw with a diamond blade. Once it was trimmed, a square piece of the rock was glued to a glass slide and cured with heat. Next, the slide was ground by hand until it was about 30 microns thick (barely visible to the naked eye).

All images were captured at 40x magnification. The images you are viewing on this page are about the size of the tip of your pencil!

Dr. Sethi does not utilize any color alteration tools when capturing the images. All images are exactly how they appeared under the polarized light microscope. 

Once Dr. Sethi captures the images, he develops the film by hand and then scans the images to the computer. Science and art become synonymous with Dr. Sethi's work.

Tropism

Tropism is the biological phenomenon that indicates growth or movement of a biological organism (usually a plant) in response to an environmental stimulus.

Photo courtesy of Mark Simmons.

The above tropism is a polarized light microscope image of adipic acid, (CH₂)₄(COOH)₂. The nearly 2.5 billion kg of adipic acid produced each year is mostly used as a monomer for the production of nylon. Other major uses involve polymers. It is a monomer for production of Polyurethane and it is used in making PVC. The image above was captured using a microscope digital camera adapter and a standard digital camera.

Polarizing Microscope Images

These polymers were captured using a Meiji MT9900 polarizing microscope and the MC2300 microscope camera.

Polarized Light Microscopy

This is a polarized light image of resorcinol at 400x magnification, courtesy of Mark Simmons. Polarized light microscopy is used primarily to view crystals, minerals, geological specimens and chemicals.

Polarized light microscopy utilizes both a polarizer and an analyzer to provide contrast in specimens. Microscopes with polarization use a polarizer positioned above the light path before the specimen, and an analyzer placed in the optical path between the objective and the eyepiece or camera port. A biological microscope or stereo microscope can have a polarizing kit added on. For advanced polarizing microscopy a polarizing microscope is used.