# Dexter Perkins

## Geology

## University of North Dakota-Main Campus

Dexter Perkins teaches geology, environmental issues, mineralogy, and ore deposits courses at the University of North Dakota where he is is Associate Director of the Harold Hamm School of Geology and Geological Engineering. His main research interests include thermodynamics of minerals and mineral systems and geoscience education.

## Website Content Contributions

### Activities (70)

Peritectic Phase Diagram part of Cutting Edge:Courses:Petrology:Teaching Examples

An exercise to help students figure out what is going on with peritectic phase diagrams. It is NOT trivial.

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Theriak-Domino Exercise part of Cutting Edge:Courses:Petrology:Teaching Examples

This multidimensional project involves using several different computer programs to calculate and interpret phase diagrams and pseudosections. So, students learn lots of skills at the same time. But, an overarching ...

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Introduction to Gibbs Energy part of Cutting Edge:Courses:Petrology:Teaching Examples

This is a short project that can be used in-class or as homework. It involves just a few questions and it is intended to help students understand the idea of Gibbs free energy.

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Calculating a Simple Phase Diagram: Diamond=Graphite part of Cutting Edge:Courses:Petrology:Teaching Examples

This is a very short exercise designed to get students to understand how the Gibbs energy equation is used to calculate the location of a reaction in P-T space. I use it in-class and have students work on it in ...

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Mineral Synthesis and X-Ray Diffraction Experiments part of Cutting Edge:Courses:Mineralogy:Activities

This 6-week laboratory activity has students working in groups of two or more to synthesize a mineral and then analyze their mineral using XRD.

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A Fun and Effective Exercise for Understanding Lattices and Space Groups part of Cutting Edge:Courses:Mineralogy:Activities

This activity uses figures from Francois Brisse as Esher drawings to teach students about 2-dimensional symmetry, especially involving translation.

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Schreinemakers Analysis - Problem #3: Analysis of an Invariant Point part of Cutting Edge:Courses:Petrology:Teaching Examples

This is a challenging Schreinemakers analysis problem.

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Schreinemakers Analysis - Problem #4 part of Cutting Edge:Courses:Petrology:Teaching Examples

This is a straightforward Schreinemakers analysis involving two invariant points.

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T-X Phase Diagrams part of Cutting Edge:Courses:Petrology:Teaching Examples

This is a 15 page tutorial and problem set designed to get students familiar with T-X diagrams, their implications, and uses.

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Reagents, Compositions, Weight Loss part of Cutting Edge:Courses:Mineralogy:Activities

This is a short experimental study of several different reagents and what happens to them when they are heated to 110° and 1200° C.

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Mineral Classification - What's in a Name? part of Cutting Edge:Courses:Mineralogy:Activities

Students derive their own scheme for identifying and naming minerals. Examples include different minerals that have the same crystal forms, and mineral species that occur with numerous forms and varieties to ...

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Examination of Igneous Silicates part of Cutting Edge:Courses:Mineralogy:Activities

Students study hand samples of light-colored igneous minerals and related mineral species. They look at some of the same minerals, and others, in thin section.

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Crystallization and Melting of Diopside - Anorthite part of Cutting Edge:Courses:Mineralogy:Activities

This short exercise introduces students to the binary phase diagram in the diopside-anorthite system that contains a eutectic invariant point.

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Synthetic Alkali Halides part of Cutting Edge:Courses:Mineralogy:Activities

This is a complex experimental investigation of the melting of alkali halides. This project takes more than one class and involves using an X-ray diffractometer.

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Mass Balance and Mineral Reactions part of Cutting Edge:Courses:Petrology:Teaching Examples

This is a short exercise to make sure that students understand mass balance and how the different starting assemblages may lead to different results after metamorphism. It is quick but not trivial.

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Mineral Classification Exercise part of Cutting Edge:Courses:Mineralogy:Activities

This exercise gets students thinking about mineral classification and the properties that are most useful for classifying and identifying minerals.

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Introduction to Ternary Phase Diagrams part of Cutting Edge:Courses:Petrology:Teaching Examples

Includes a number of hands-on exercises involving ternary phase diagrams. Some questions are quite easy, some are not.

Making Good Looking Diagrams from Theriak-Domino Output part of Cutting Edge:Courses:Petrology:Teaching Examples

This is a complementary exercise that follows "Using Theriak-Domino to Calculate Equilibrium Phase Diagrams." I have students do this because it brings closure to the other exercise and it teaches ...

TWQ Exercise part of Cutting Edge:Courses:Petrology:Teaching Examples

This is an exercise using TWQ to generate a phase diagram. It can be used as homework but is better done in a group.

Compatibility Diagram 3: Fo-Tc-Etc part of Cutting Edge:Courses:Petrology:Teaching Examples

One of three compatibility diagrams I use in class. This is a bit more complicated than #1 and #2. It involves a projection from H2O and non-standard corners on the composition triangle.

Compatibility Diagram 2:Tc-En-Etc part of Cutting Edge:Courses:Petrology:Teaching Examples

One of three compatibility diagrams I use in class. This is a short activity that has students construct several compatibility diagrams in different fields on a phase diagram. This, in turn, can be followed by ...

Compatibility Diagram 1: Dsp-Py-Qz-Ka-H2O part of Cutting Edge:Courses:Petrology:Teaching Examples

One of three compatibility diagrams I use in class. This is a short activity to introduce students to compatibility diagrams (triangular diagrams showing stable assemblages) and how tie lines change when a reaction ...

Plane Groups part of Cutting Edge:Courses:Mineralogy:Activities

Studying plane groups is a good way to introduce crystal systems, point groups, lattices, symmetry operators, etc. All is in 2-D, but it is easy to tell students that the principles are the same in 3-D. I provide, ...

Three Component Systems part of Cutting Edge:Courses:Petrology:Teaching Examples

This exercise involves plotting mineral compositions on triangular (3-component diagrams) and using those diagrams to determine possible mineral reactions.

Phase Diagrams and Chemographic Projections part of Cutting Edge:Courses:Petrology:Teaching Examples

This exercise is a good way to get students thinking about the phase rule, metastable and stable reactions and phase diagrams. It can be done in class or as homework.

Simple Eutectic Exercise: Diopside-Anorthite part of Cutting Edge:Courses:Petrology:Teaching Examples

This exercise can be done in-class (I use it as a group activity) or as homework. It is a quick way to get students to figure out how to use and interpret simple eutectic diagrams.

Plotting Compositions in 2-D and 3-D Space part of Cutting Edge:Courses:Petrology:Teaching Examples

This is a fairly short exercise that can be used for an in-class cooperative learning project or as homework. It includes LOTS of explanation and so is sort of a tutorial. I use it in my petrology class because it ...

Naming Igneous Rocks part of Cutting Edge:Courses:Petrology:Teaching Examples

This project is intended to introduce students to the IUGS rock classification scheme. Samples come from the Wards Collections (which many schools have). Students are provided with both hand specimens and thin ...

Plagioclase Phase Diagram part of Cutting Edge:Courses:Petrology:Teaching Examples

This is a short exercise aimed at evaluating whether students understand how to interpret the Ab-An phase diagram.

Growing Crystals on a Microscope Stage part of Cutting Edge:Courses:Mineralogy:Activities

Many compounds crystallize rapidly from evaporating solutions, and many can be crystallized from melts. Because of this, it is possible to do simple crystallization experiments and to watch crystals grow over short ...

Schrinemaker Analysis - Problem #1: Analysis of an Invariant Point part of Cutting Edge:Courses:Petrology:Teaching Examples

This is a standard Schreinemakers problem: identifying the sequence of stable and metastable reactions around an invariant point.

Schreinemakers Analysis - Problem #2: Analysis of an Invariant Point with Application of the Clausius-Clapeyron Equation part of Cutting Edge:Courses:Petrology:Teaching Examples

This is a standard Schreinemakers problem: identifying the sequence of stable and metastable reactions around an invariant point. The added wrinkle is that they use the Clausius-Clapeyron Equation to calculate ...

Mole %, Weight %, Compositions and Projections part of Cutting Edge:Courses:Petrology:Teaching Examples

This is an introductory exercise intended to get students thinking about mole vs weight % and about the power and problems of projections.

Properties of Minerals part of Cutting Edge:Courses:Mineralogy:Activities

Students examine a number of key mineral properties and how they are displayed by different minerals.

Properties of Minerals and Intro to Polarizing Microscopes part of Cutting Edge:Courses:Mineralogy:Activities

This exercise continues the study of the physical properties of minerals and introduces petrographic microscopes.

Private Mineral Project - Part 1 part of Cutting Edge:Courses:Mineralogy:Activities

Students begin to work on semester-long private mineral projects.

Crystallizing Minerals from Aqueous Solutions part of Cutting Edge:Courses:Mineralogy:Activities

Students dissolve selected salts and other compounds in water, let the water evaporate, and examine the crystals that grow.

First Look at Crystal Shapes part of Cutting Edge:Courses:Mineralogy:Activities

This is a short and simple exercise requiring students to examine and compare different crystal shapes.

Mafic Mineral Properties and Thin Sections part of Cutting Edge:Courses:Mineralogy:Activities

Students look at mafic igneous minerals, learning to distinguish and identify them in hand specimen. They also look at a few of the minerals in thin section.

Plagioclase Phase Diagram part of Cutting Edge:Courses:Mineralogy:Activities

This short exercise involves the binary plagioclase "two-phase loop" phase diagram.

A Last Look at Igneous Minerals in Thin Section part of Cutting Edge:Courses:Mineralogy:Activities

A final lab exercise that uses the optical mineralogy skills learned in the previous labs, and begins the transition to petrographic analysis of thin sections.

Sedimentary and Related Minerals part of Cutting Edge:Courses:Mineralogy:Activities

This exercise is an introduction to sedimentary minerals and rocks.

Fun With Asbestos part of Cutting Edge:Courses:Mineralogy:Activities

This exercise is a practical application of optical mineralogy involving identification of some asbestiform minerals.

X-ray Analysis of Sand part of Cutting Edge:Courses:Mineralogy:Activities

This is an x-ray diffraction analysis of six sand samples and comparison with hand specimens.

Metamorphic Rocks and Minerals part of Cutting Edge:Courses:Mineralogy:Activities

This exercise is an introduction to the most important metamorphic rocks and minerals.

Phase Equilibria part of Cutting Edge:Courses:Mineralogy:Activities

This is a short exercise that introduces basic thermodynamics.

Ore Minerals part of Cutting Edge:Courses:Mineralogy:Activities

Introduction to sulfides and other ore minerals.

Mineral Commodities part of Cutting Edge:Courses:Mineralogy:Activities

This exercise introduces students to mineral commodities.

Symmetry part of Cutting Edge:Courses:Mineralogy:Activities

This is an introduction to the basic symmetry elements.

Using SHAPE to Make Crystal Drawings part of Cutting Edge:Courses:Mineralogy:Activities

In this exercise, students use SHAPE, a computer graphics program, to make crystal drawings.

Point Groups part of Cutting Edge:Courses:Mineralogy:Activities

This exercise involves identifying symmetry in crystals and using that information to assign crystals to crystal systems and point groups.

Symmetry Summary part of Cutting Edge:Courses:Mineralogy:Activities

This summary exercise involves crystal system and point group identification and stereo diagram construction.

Introduction to Crystal Structures: Bond Strength (Pauling's Rule #2) part of Cutting Edge:Courses:Mineralogy:Activities

A look at Pauling's "electrostatic valency" principle.

Introduction to Crystal Structure: Bond Strength part of Cutting Edge:Courses:Mineralogy:Activities

This is an exercise to get students thinking about coordination number and bond strength It is really an application of Pauling's Rules, mostly rule #2

Interpreting T-X Diagrams part of Cutting Edge:Courses:Petrology:Teaching Examples

This exercise is designed to help students learn how to interpret T-X phase diagrams. It also introduces them to the systematics of reactions involving a group of minerals.

Phase Diagrams part of Cutting Edge:Courses:Petrology:Teaching Examples

This is a somewhat lengthy homework assignment that introduces students to phase diagrams. It is a tutorial that stands alone and does not need much introduction.

Introduction to Mineral Equilibria part of Cutting Edge:Courses:Petrology:Teaching Examples

This activity features a short problem set to be used in class. It helps focus the discussion, while providing a starting point for an introduction to mineral reactions and phase diagrams.

AFM Diagram Quiz part of Cutting Edge:Courses:Petrology:Teaching Examples

This is a short problem set I use to determine if students know how to interpret AFM diagrams. I call it a quiz but it is really more of a learning experience. It works well as an in-class group exercise.

Collection of PT Phase diagram exercises part of Cutting Edge:Courses:Petrology:Teaching Examples

I am always needing more phase diagrams exercises so my students can practice problem solving. This collection includes 5 different exercises that can be used for homework, in-class, or for quizzes or exams.

Water Development: A Philosophical and Ethical Issue part of GeoEthics:Activities

Dexter Perkins, University of North Dakota Summary This is a seven part module that deals with water development. The goal is to get students thinking about water development in terms of its appropriateness, and ...

Identifying Symmetry in 2-D Drawings part of Cutting Edge:Courses:Mineralogy:Activities

These three activities are problem sets that make students think about symmetry in 2-D. They all involve identifying symmetry from drawings. I purposely omitted jargony words/phrases such as lattice, unit cell, ...

A Field Trip to See a Cross Section of the Crust and Samples of the Mantle part of NAGT:Teaching Resources:Teaching in the Field:Field Trip Collection

Dexter Perkins Dept. of Geology and Geological Engineering The University of North Dakota Grand Forks ND 58202 Intended Audience: Undergraduate geology majors or members of a geology club. Location: This field ...

Simple Peritectic Exercise: Leucite-Quartz part of Cutting Edge:Courses:Petrology:Teaching Examples

This can be done as an in-class exercise (I use it as a group project) or as homework. It is intended to help students learn how to interpret and use peritectic diagrams.

Three Component Systems and Their Reactions part of Cutting Edge:Courses:Petrology:Teaching Examples

This exercise involves plotting mineral compositions on triangular (3-component diagrams) and using those diagrams to determine possible mineral reactions.

Stereo Diagrams part of Cutting Edge:Courses:Mineralogy:Activities

This exercise is an introduction to stereo diagrams.

X-ray Analysis of Unknown Minerals part of Cutting Edge:Courses:Mineralogy:Activities

In this exercise, students use X-ray analysis to identify unknown minerals.

Mineral Structure 2 part of Cutting Edge:Courses:Mineralogy:Activities

Introduction to some basic crystal structures.

Private Mineral Gallery Walk part of Cutting Edge:Courses:Mineralogy:Activities

Public display of "private mineral" posters created by students and a group learning session based on the posters.

Mineral Structure 3 part of Cutting Edge:Courses:Mineralogy:Activities

Introduction to silicate structures.

Photographing Minerals part of Cutting Edge:Courses:Mineralogy:Activities

Students take digital photographs of mineral specimens and learn how to manipulate them with Photoshop.

### Course (1)

Mineralogy Course Summary and Goals part of Cutting Edge:Course Design:Goals Database

This class is an introduction to fundamental mineralogy and mineralogical principles. The course is taught as a studio course and implements spiral learning. Significant emphasis is placed on helping students ...

### Teaching Method Module (1)

Studio Teaching in the Geosciences part of Starting Point-Teaching Entry Level Geoscience:Studio Teaching in the Geosciences

Compiled by Dexter Perkins at The University of North Dakota What is a Studio Classroom? – A classroom where students work in groups and are responsible for their own learning Studio classrooms are not all ...

### Essays (3)

The Most Engaging Class part of Earth and Mind:Posts

Earth and Mind is excited to have its first guest post. Dr. Dexter Perkins teaches geology, environmental issues, mineralogy, and ore deposits courses in the Geology Department at the University of North Dakota. ...

Dexter Perkins part of Cutting Edge:Develop Program-Wide Abilities:Metacognition:Workshop 08:Participant Essays

Metacognition: Thinking about Thinking and Learning Dexter Perkins, Department of Geology and Geological Engineering, University of North Dakota Starting in 1948, Benjamin Bloom and coworkers developed a ...

Dexter Perkins part of Cutting Edge:Enhance Your Teaching:Affective Domain:Workshop 07:Workshop Participants

Department of Geology, University of North Dakota Homepage What are the key issues related to the role of the affective domain in teaching geoscience that you would like to engage at the workshop? Hard to say. The ...

### Other Contributions (16)

Reflection After Exam #1 part of Cutting Edge:Develop Program-Wide Abilities:Metacognition:Activities

Students did poorly on the first exam, so I borrowed and modified this exercise. It is intended to get them to think about what THEY can do to improve performance on future exams. The original idea came from Marsha ...

Mineralogy: University of North Dakota part of Starting Point-Teaching Entry Level Geoscience:Studio Teaching in the Geosciences:Examples

This class is an introduction to fundamental mineralogy and mineralogical principles. The course is taught as a studio course, and significant emphasis is placed on helping students develop holistic learning ...

Introduction to X-ray diffraction part of Cutting Edge:Courses:Mineralogy:Activities

Students collect X-ray diffraction patterns for the experimental products obtained in a lab on Reagents, Compositions, Weight Loss.

Knowledge Surveys part of Cutting Edge:Student Learning: Observing and Assessing:Activities

Knowledge Surveys consist of a series of questions that cover the full content of a course. The questions are designed to illustrate the different levels of understanding required for mastery of the content. Knowledge surveys can serve as both formative and summative assessment tools.

Advanced Modeling Programs: Theriak-Domino part of Integrating Research and Education:Teaching Phase Equilibria

Dexter Perkins, The University of North Dakota What is it? The THERIAK-DOMINO software is a program collection written by Christian de Capitani (Mineralogy and Petrology Institute, University of Basel, ...

Clapeyron Equation part of Integrating Research and Education:Teaching Phase Equilibria

Andrea Koziol (University of Dayton) and Dexter Perkins (University of North Dakota) The Clapeyron equation (also called the Clausius-Clapeyron equation) relates the slope of a reaction line on a phase diagram to ...

Deriving and Balancing Metamorphic Reactions part of Integrating Research and Education:Teaching Phase Equilibria

Dexter Perkins (University of North Dakota) A four page summary (Acrobat (PDF) 33kB Jul31 07) is available which can be used as a class handout. Given a list of minerals, how do we determine all the possible ...

Activity Models part of Integrating Research and Education:Teaching Phase Equilibria

Dex Perkins, University of North Dakota; Andrea Koziol, University of Dayton; and Dave Mogk, Montana State University Introduction Minerals may have many different compositions in nature and, therefore, the ...

Fundamental Thermodynamic Calculations part of Integrating Research and Education:Teaching Phase Equilibria

Dexter Perkins (University of North Dakota), Andrea Koziol (University of Dayton), John Brady (Smith College) The basis for calculating a reaction curve (a curve/line on a phase diagram) is the understanding that ...

Pseudosections part of Integrating Research and Education:Teaching Phase Equilibria

Dave Hirsch, Western Washington University, Julie Baldwin, University of Montana, and Dexter Perkins, University of North Dakota What is a Pseudosection? A pseudosection, also called an equilibrium phase diagram, ...

Gibbs Free Energy and Other Thermodynamic Functions part of Integrating Research and Education:Teaching Phase Equilibria

Dexter Perkins (University of North Dakota), Andrea Koziol (University of Dayton), John Brady (Smith College) and β, both with the same composition. The mineral with the lowest Energy is stable. Here we see ...

Thermodynamics part of Integrating Research and Education:Teaching Phase Equilibria

Dexter Perkins (University of North Dakota), Andrea Koziol (University of Dayton), John Brady (Smith College) A short (13 page)summary (Acrobat (PDF) 212kB Nov11 07) (including several of the most significant ...

Phase Diagrams (and Pseudosections) for Petrologists part of Integrating Research and Education:Teaching Phase Equilibria

Compiled by Dexter Perkins (University of North Dakota) and John Brady (Smith College) Standard phase diagrams are graphical representations of the equilibrium relationships between minerals (or others phases). ...

Method of Schreinemakers A Geometric Approach to Constructing Phase Diagrams part of Integrating Research and Education:Teaching Phase Equilibria

Dexter Perkins, University of North Dakota and Dave Mogk, Montana State University If you would like an 13-page long summary of the information presented on this page, perhaps to use as a class handout, click link ...

Mineral Formulae Recalculation part of Integrating Research and Education:Teaching Phase Equilibria

John Brady, Smith College and Dexter Perkins, University of North Dakota What is it? Chemical analyses for silicate minerals are commonly reported in weight percentages of the oxides of the elements determined. ...

Advanced Modeling Programs: Introduction to the THERMOCALC Mineral Equilibria Modeling Software part of Integrating Research and Education:Teaching Phase Equilibria

Julie Baldwin, University of Montana; Dexter Perkins, University of North Dakota; and Dave Mogk, Montana State University What is it? THERMOCALC is thermodynamic calculation software for tackling mineral ...

## Communities

38 activities reviewed