Optical mineralogy

You have reached the home page for the Year 2 Optical Mineralogy course offered at Brock University. These web pages, like all others, are constantly being updated. Currently the browser may burrow deeper into the course. Links are provided to full course notes, handouts, all overheads and an outline of the labs for the course.

Properties of light and its interaction with mineral grains: reflection, refraction, polarization, interference phenomena, extinction, color and pleochroism. Refractometry; isotropic, uniaxial and biaxial optics; interpretation of interference figures. Transmitted light petrography in the identification and familiarization with major rock forming minerals in grain mounts and thin section.

Instructor: Greg Finn, 13th Floor, Schmon Tower, (greg.finn@brocku.ca)
Lectures: Monday, Wednesday and Friday 8:00 AM; Room D319
Labs: Monday 2:00 to 5:00; Room D308

Recommended Text

Introduction to Optical Mineralogy, third of fourth edition, by William D. Neese. This text is available in the bookstore and will be used in this course and all petrology courses offered at Brock. It will serve as a handy reference for use in the real world after graduation.


Supplementary Texts – Available in the Main Library

  • Bloss – An Introduction to the Methods of Optical Mineralogy
  • Kerr – Optical Mineralogy
  • Phillips – Mineral Optics, Principles and Techniques
  • Deer, Howie and Zussman – Rock Forming Minerals. A 7 volume set, invaluable to petrologists.
  • Deer, Howie and Zussman – Introduction to Rock Forming Minerals. A condensed version of the 7 volume set.
  • Ehlers – Optical Mineralogy Volumes 1 and 2
  • MacKenzie and Guilford – Atlas of rock-forming minerals in this section

Midterm         15%
Final                35%
Labs                 30%
Lab Exam        15%
Spotting Quiz    5%

The following is a list of lecture topics to be considered in this course.


Properties of Light (PDF File)

Refractometry (PDF File)

Isotropic Materials (PDf File)

Anisotropic Minerals (PDF File)

Optical Properties (PDF File)

Uniaxial Minerals

Two Lecture PDF Files to Download and Print
Uniaxial Optics I and II (PDF File)
Uniaxial Interference Figures (PDF File)

Uniaxial Minerals – Optical Properties, Descriptions and Pictures (PDF FIle)

Optical Properties
Apatite Calcite Nepheline
Quartz Tourmaline Zircon

Biaxial Minerals

Several Lecture PDF Files to Download and Print

Biaxial Optics I (PDF File)
Biaxial Interference Figures (PDF File)
Biaxial Optic Sign (PDF File)
Biaxial Minerals – Other Properties (PDF File)

Biaxial Minerals – Web Pages

Optical Properties
Olivine Orthopyroxene Clinopyroxene
Hornblende Tremolite – Actinolite Plagioclase
Biotite Muscovite Chlorite
Microcline Orthoclase Sanidine

Biaxial Minerals –Lecture PDF Files

Optical Properties
Olivine Orthopyroxene Clinopyroxene
Hornblende Tremolite – Actinolite Plagioclase
Biotite Muscovite Chlorite
Microcline Orthoclase Sanidine

Other Minerals

Known Minerals – How to Describe Them?
Unknown Minerals – What To Do!
PDF Files to download:
Known Minerals – How to Describe Them? (PDF File)
Unknown Minerals – What To Do! (PDF File)

Part I – Lab Outline

The lab component of this course accounts for 50% of the final grade, 30% for the labs, 5 % for determining the refractive index of an isotropioc mineral and 15% for the lab exam. The latter will involve the identification of minerals or specific optical properties for a given sample in a spotting quiz and the identification of the minerals within a single thin section.
In the lab portion of this course the following will be covered.

Mineral Optics

The first item to be introduced will be the petrographic microscope. All remaining labs will involve the use of the microscope and the interaction of the light with the mineral, in grain mount or in thin section to define the optical properties used in identification and recognition.

Mineral Identification

At the completion of the course you should be able to identify 8-10 major minerals or groups of minerals

  1. garnet, fluorite, halite
  2. calcite
  3. quartz, nepheline, apatite, tourmaline, zircon
  4. olivine
  5. pyroxenes (orthopyroxene, clinopyroxene)
  6. amphiboles (hornblende, tremolite-actinolite)
  7. micas (biotite, muscovite, chlorite)
  8. feldspars (plagioclase, microcline, orthoclase, sanidine)

Identification of Unknowns

With the information and techniques obtained in the labs and from the lecture material you will have the ability to identify an unknown mineral present in a thin section or a grain mount. (You will be doing this for the first time in the lab exam.)

Part II – Lab Schedule

Lab #/Lab Topic

  1. Introduction to the Petrographic Microscope
  2. Becke Line and Refractive Index Determination
  3. Double Refraction and Refractive Index
  4. Uniaxial Minerals – Refractive Index Determination
  5. Uniaxial Minerals – Interference Figures
  6. Uniaxial Minerals – Identification and Spotting Quiz
  7. Biaxial Minerals – Optical Properties and Indicatrix
  8. Biaxial Minerals – Interference Figures
  9. Pyroxenes – Optical Properties and Identification
  10. Amphiboles and Micas – Optical Properties and Identification
  11. Feldspars – Optical Properties and Identification
  12. Lab Exam (Spotting Quiz and Mineral Identification)

Lab Regulations

  1. All labs are to be submitted to the instructor at the end of the Wednesday lecture immediately following the lab period. Late labs will be subject to a penalty of 20% per day and will not be accepted after five (5) consecutive days.
  2. Microscopes will be assigned in the first lab to all students, with no charge for microscope key rental. The key is to be returned immediately following the Lab Exam. Failure to return the key will result in a grade of IN 35 (Incomplete) for the course, regardless of the actual grade.