This book presents a guide of optical mineralogy for beginners and microscopists who need to brush up their knowledge. It allows the fast identification of common rock-forming minerals in a thin section using a polarized light microscope and transmitted plane and cross polarized light. The book summarizes essential principles of optical mineralogy in numerous schemes. It explains, with the aid of more than 1000 microscopic images, how to determine the diagnostic optical characteristics of a mineral in a thin section. Seventy-two mineral plates of sixty-five common rock-forming minerals comprising typical microscopic images in plane and cross polarized light illustrate the most important optical and crystallographic parameters and their diagnostic characteristics and typical appearance in various geological settings. The original approach of the book is to facilitate mineral identification by mineral plates organized according to color in transmitted plane polarized light and, in each color category, according to decreasing maximum birefringence in cross polarized light. In addition, two chapters are devoted to the classification of magmatic and metamorphic rocks and their common mineral parageneses and textures.The book reflects the author’s experience of teaching optical mineralogy in the most efficient way possible to generations of students at the Universities of Heidelberg (Germany), Basel (Switzerland), and Geneva (Switzerland).
Author(s): Susanne Theodora Schmidt
Series: Springer Textbooks in Earth Sciences, Geography and Environment
Publisher: Springer
Year: 2023
Language: English
Pages: 286
City: Cham
Acknowledgements
Contents
1 Introduction
A Selection of Books on Optical Mineralogy, Books with a Chapter on Optical Mineralogy, and Publications Relevant to the Subject
Further Reading
2 Basic Concepts
2.1 Light as the Tool of Examination in Optical Mineralogy
2.3 Retardation of Rays in Anisotropic Minerals and Birefringence
2.4 Passage of Light Through Crystalline Matter: Optic Orientation and the Optical Indicatrix
2.5 Location of the Optical Indicatrix with Reference to the Crystal Systems and Crystallographic Directions
2.5.1 Location of the Optical Indicatrix in Isotropic Minerals
2.5.2 Location of the Optical Indicatrix in Uniaxial Minerals
2.5.3 Location of the Optical Indicatrix in Biaxial Minerals
2.6 Understanding How a Mineral is Cut in a Thin Section
References and Suggested Further References
Further Reading
3 The Petrographic Microscope: A Polarized Light Microscope
3.1 Substage Assembly
3.2 Upperstage Assembly
3.3 Circular Rotating Microscopic Stage and Objective Lens Revolver
3.4 Objective Lenses
3.5 Accessory Plates (Retardation Plates, Compensator Plates)
3.6 Adjustment of the Microscope
3.6.1 Checking the Orientation of the Polarizer and the Correct Alignment of the Analyzer
3.6.2 Adjustment of the Oculars
3.6.3 Centering the Objective Lenses
3.6.4 Calibrating the Ocular Micrometer
3.6.5 Adjustment of the Aperture Diaphragm
3.6.6 Focusing and Centering the Condenser
3.6.7 Adjustment of the Field Diaphragm
3.7 The Object of Study: The Thin Section
3.8 Illumination and Comfort While Working at the Microscope
References and Suggested Further Reading
4 Optical Properties of Minerals in Plane Polarized Light (PPL)
4.1 Color and Pleochroism
4.1.1 Appearance of Color in Thin Section
4.1.2 Intensity of Color
4.1.3 Pleochroism
4.1.4 Causes of Color
4.2 Crystal Habit and Textural Relationships
4.2.1 Appearance of Crystal Habit
4.2.2 Causes of Different Habit
4.3 Relief
4.3.1 Appearance of relief
4.3.2 Mathematical Formulation of Relief Formation Between Air and Mineral
4.3.3 Formation of Relief Between Minerals and the Becke Line Method
4.4 Cleavage
4.4.1 Appearance of Cleavage
4.4.2 Causes of cleavage
References
Further Reading
5 Optical Properties of Minerals in Cross Polarized Light (XPL)
5.1 Birefringence
5.1.1 Appearance of Birefringence
5.1.2 The Michel-Lévy and the Raith-Sørensen Interference Color Charts
5.1.3 How to Determine the Maximum Interference Color of a Mineral
5.1.4 Transmission of Light by the Analyzer and Extinction Behavior
5.1.5 Extinction Angle and Types of Extinction
5.2 Elongation
5.3 Twinning
5.3.1 Appearance of Twinning
5.3.2 Types of Twinning
5.3.3 Causes of Twinning
5.4 Crystal Zoning
5.4.1 Oscillatory Zoning
5.4.2 Concentric Zoning
5.4.3 Sector or Sectoral Zoning
References
Further Reading
6 Conoscopic Observations and Interference Figures
6.1 Interference Figures of Uniaxial Minerals
6.1.1 Uniaxial Centered Optic Axis Figure (OA Figure)
6.1.2 Uniaxial Off-Centered Interference Figure
6.1.3 Flash Figure of Uniaxial Minerals
6.1.4 Genge’s Birefringence Ball of Uniaxial Minerals
6.2 Interference Figures of Biaxial Minerals
6.2.1 Bxa Figure
6.2.2 Biaxial-Centered Optic Axis Figure (OA Figure)
6.2.3 Flash Figure of Biaxial Minerals
6.2.4 Genge’s Birefringence Ball of Biaxial Minerals
6.2.5 Determination of the 2V Angle in Biaxial Minerals
6.3 How to Obtain an Interference Figure
References and Books with Chapters on Conoscopic Observations
Further Reading
7 Igneous Rocks: Some Basic Concepts
7.1 Classification of Igneous Rocks
7.1.1 Classification Based on Modal Composition
7.1.2 Classification Based on Texture
7.2 Chemical Classification of Igneous Rocks
References and Suggested Further Reading
Further Reading
8 Metamorphic Rocks: Some Basic Concepts
8.1 Classification of Metamorphic Rocks
8.1.1 Textures of Metamorphic Rocks
8.1.2 Modal Composition and Mineral Assemblage
8.1.3 Protolith
8.2 Common Textures in Metamorphic Rocks
Selection of Books on Metamorphic Petrology and Cited Reference
Further Reading
9 The Mineral Plates and How to Use Them
9.1 Introduction to the Mineral Plates
9.2 Mineral Plates
Some References for the Determination of Minerals in Thin Section
Further Reading
Appendix_1
Appendix_2
Appendix_3
Index
