Identification Chart for the Rock-Forming Minerals by Polarizing Microscope and Interference Color Chart: Hard Plastic Plate

Distributed by the Geological Society of Japan
(300 Yen ($3) for non-member; 200 Yen ($2) for member)

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Identification Chart for the Rock-Forming Minerals by Polarizing Microscope
(by Akira Ishiwatari)

Minerals are arranged by their color, refractive index, and cleavage (observed under an "open nicol") into eight groups (1 to 8), which are easily descernible as horizontal colored bands in the chart (right). They are further classified into seven vertical columns (A to G) by their optic character and optic axial angle observed under "crossed nicols" with a conoscope. Magnitude of birefringence (interference), signs of elongation, nature of twins, abnormal interference color, degree of dispersion, and color zoning are indicated by various symbols.

On-line version of this table is available in the following site:

Black-and-white charts in English and Japanese were bublished in the following article:


Ishiwatari, A. (1999) An easy identification chart for major rock-forming minerals by polarizing microscope. Jour. Geol. Soc. Japan, 105 (2), 156-158.

Interference Color Chart (by Takenori Kato of Nagoya University)

This chart displays interference color with the corresponding range of birefringence of many minerals. This chart was produced using a personal computer by the method described in the following papers:


Kato, T. (2001) A method to synthesize interference color chart with personal computer. Jour Geol. Soc. Japan, 107, 64-67.

Kato, T. (2001) Synthesized interference color chart with personal computer. Jour. Geol. Soc. Japan, 107, I-II.

The two charts are printed on the two sides of a single, hard plastic plate. Please keep this plate aside your polarizing microscope.

2001/05/23 Produced, 2003/08/26 Renewed