OpticalMine 3.0

Optical Mineralogy

Study of minerals with the petrographic microscope


Carlos Dorronsoro Díaz*, Bernabé Dorronsoro Díaz**, Carlos Dorronsoro Fdez*** and Arturo García Navarro ****

* Instituto de Optica "Daza Valdés". Consejo Superior de Investigaciones Científicas. Madrid

** Dpto. Lenguas y Ciencias de la computación. Facultad de Ingeniería Informática. Universidad de Málaga

*** Dpto Edafología. Facultad de Ciencias. Universidad de Granada

**** Dpto Edafología. Facultad de Ciencias. Badajoz. Univ Extremadura


Translated into English by Gillian Butcher



This programme aims to study how and why optical properties are presented by minerals under the transmitted light petrographic microscope.

The most common method for studying the constituent minerals of rocks and soils is by examining the optical properties shown by minerals with a polarising, or petrographic microscope.

The procedure involves analysing the optical phenomena that occur when polarised light is passed through the minerals.



The petrographic microscope

The light

Thin sections

Basic theoretical concepts


2. PPL







3. XPL using orthoscopic illumination

Interference colour

Extinction angle

Sing of elongation



4. XPL using conoscopic illumination

Interference figures

Optic sign



5. References


6. Agradecimientos