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.
- Start here to access the Course Outline (PDF file)
- SAMPLE 2P22 MIDTERM
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
Lectures;
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
Evaluation
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.
Objectives
Properties of Light (PDF File)
- Introduction
- Electromagnetic Radiation
- Wave Front, Wave Normal
- Phase and Interference
- Reflection and Refraction
- Polarization of Light
Refractometry (PDF File)
- Relief
- Becke Line
Isotropic Materials (PDf File)
Anisotropic Minerals (PDF File)
Optical Properties (PDF File)
- Extinction
- Accessory Plates
- Vibration Directions in Minerals
- Sign of Elongation
- Relief and Pleochroism
Uniaxial Minerals
Two Lecture PDF Files to Download and Print
Uniaxial Optics I and II (PDF File)
Uniaxial Interference Figures (PDF File)
- Uniaxial Optics
- Uniaxial Optic Sign
- Paths Followed by Light
- Uniaxial Indicatrix
- Birefringence and Interference Colours
- Extinction in Uniaxial Minerals
- Pleochroism in Uniaxial Minerals
- Interference figures
- How to obtain an Interference Figure
- Optic Axis Figure
- Interference Figure
- Formation of the Isochromes
- Formation of the Isogyres
- Optic Sign Determination
- Off-Centred Optic Axis Figure
- Uniaxial Flash Figure
- Summary of Uniaxial Interference Figures
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 Optics
- Biaxial Indicatrix
- Optic Sign
- Crystallographic Orientation and the Indicatrix
- Biaxial Inteference Figures
- Acute Bisectrix Figure (Bxa)
- Formation of the Isochromes
- Vibration Directions and Formation of the Isogyres
- Rotation of the Isogyre
- Centred Optic Axis Figure
- Obtuse Bisectrix Figure (Bxo)
- Optic Normal or Biaxial Flash Figure
- Off Centred Figures
- Optic sign determination
- Acute Bisectrix Figure
- Obtuse Bisectrix Figure
- Optic Axis Figure
- Optic Normal
- Identifying Grains Which Will Produce Usable Interference Figures
- Other Properties of Biaxial Minerals
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
- garnet, fluorite, halite
- calcite
- quartz, nepheline, apatite, tourmaline, zircon
- olivine
- pyroxenes (orthopyroxene, clinopyroxene)
- amphiboles (hornblende, tremolite-actinolite)
- micas (biotite, muscovite, chlorite)
- 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
- Introduction to the Petrographic Microscope
- Becke Line and Refractive Index Determination
- Double Refraction and Refractive Index
- Uniaxial Minerals – Refractive Index Determination
- Uniaxial Minerals – Interference Figures
- Uniaxial Minerals – Identification and Spotting Quiz
- Biaxial Minerals – Optical Properties and Indicatrix
- Biaxial Minerals – Interference Figures
- Pyroxenes – Optical Properties and Identification
- Amphiboles and Micas – Optical Properties and Identification
- Feldspars – Optical Properties and Identification
- Lab Exam (Spotting Quiz and Mineral Identification)
Lab Regulations
- 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.
- 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.
A collection of plane light and crossed polarized views of 27 common isotropic, uniaxial and biaxial minerals. Each individual mineral page also contains a summary of the optical properties useful in recognition. The minerals represent those covered in Optical Mineralogy (ERSC 2P22) with the remainder being introduced in Igneous and Metamorphic Petrology (ERSC 3P21).
OPTICAL PROPERTIES OF COMMON MINERALS
Select one of the minerals listed below to get a summary of the optical data and view representative plane light and crossed polar images. The minerals listed below are those which are introduced in ERSC 2P22 — Optical Mineralogy and 3P21 — Petrology and Petrography at Brock.