Cutting Edge > Courses > Mineralogy > Teaching Activities > Crystal Structures as Geobarometers

Crystal Structures as Geobarometers

Kent Ratajeski
Montana State University
Author Profile


In this exercise, designed for undergraduate igneous petrology or advanced mineralogy courses, students download a series of crystal structures from the American Mineralogist Crystal Structure Database to explore the crystal-chemical basis that allows the clinopyroxene crystal structure to be used as a geobarometer.

Used this activity? Share your experiences and modifications



mid to upper level undergraduate petrology course

Skills and concepts that students must have mastered

How the activity is situated in the course


Content/concepts goals for this activity

Higher order thinking skills goals for this activity

Other skills goals for this activity

Description of the activity/assignment

This exercise is based on the recent formulation of a geobarometer based on the crystal structure of clinopyroxene (Nimis, 1995; 1998; 1999). This method relates structural parameters (e.g., the volumes of the unit cell and the M1 polyhedron) to the pressure at which the mineral crystallizes within basic and ultrabasic magmas.

Determining whether students have met the goals

More information about assessment tools and techniques.

Download teaching materials and tips

Other Materials

Supporting references/URLs

The problem set can be found at Crystal Structures as Geobarometers. This site provides a tutorial with step by step instructions on how to find, download and render the data to emulate findings reported by Nimis (1995, 1998, and 1999).

See more Teaching Activities »