OPTICAL MINERALOGY LABORATORY SCHEDULE
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 beginning of the Thursday 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.
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