Optical Mineralogy: Principles and Practice

ISBN-13: 9781461596943 / Angielski / Miękka / 2013 / 303 str.

C. D. Gribble

Opis

This book is the successor to A practical introduction to optical mineralogy, which was written in the early 1980s, and published by George Allen & Unwin in 1985. Our intention, once again, is to introduce the student of geology to the microscopic examination of minerals, by both transmitted and reflected light. These techniques should be mastered by students early in their careers, and this text has been proposed in the full awareness that it will be used as a laboratory handbook, serving as a quick reference to the properties of minerals. However, care has been taken to present a systematic explanation of the use of the microscope, as well as to include an extended explanation of the theoretical aspects of optical crystallography in transmitted light. The book is therefore intended as a serious text that introduces the study of minerals under the microscope to the intending honours student of geology, as well as providing information for the novice or interested layman.

Spis treści

1 Introduction to the microscopic study of minerals.- 1.1 Introduction.- 1.2 The transmitted-light microscope.- 1.3 The appearance of thin sections using transmitted-light microscopy.- 1.4 Systematic description of minerals in thin section using transmitted light.- 1.4.1 Properties in plane polarized light.- 1.4.2 Properties under crossed polars.- 1.5 The reflected-light microscope.- 1.6 The appearance of polished sections under the reflected-light microscope.- 1.7 Systematic description of minerals in polished section using reflected light.- 1.7.1 Properties observed using plane polarized light (PPL).- 1.7.2 Properties observed using crossed polars.- 1.7.3 The external nature of grains.- 1.7.4 Internal properties of grains.- 1.7.5 Vickers hardness number (VHN).- 1.7.6 Distinguishing features.- 1.8 Observations using oil immersion in reflected-light studies.- 1.9 Polishing hardness.- 1.10 Microhardness (VHN).- 1.11 Practical points on the use of the microscope (transmitted and reflected light).- 1.12 Preparation of thin and polished sections.- 2 Silicate minerals.- 2.1 Crystal chemistry of silicate minerals.- 2.2 Mineral descriptions.- AlSiO5 polymorphs 41; Amphibole group 47; Beryl 63; Chlorite group 63; Chloritoid 65; Clay minerals 66; Cordierite 69; Epidote group 71; Feldspar group 78; Feldspathoid family 97; Garnet group 101; Humite group 103; Melilite group 106; Mica group 107; Olivine group 112; Pumpellyite 118; Pyroxene group 119; Scapolite 138; Serpentine 139; Silica group 140; Sphene 145; Staurohte 147; Talc 149; Topaz 150; Tourmaline group 151; Vesuvianite 152; Zeolite group 152; Zircon.- 3 The non-silicates.- 3.1 Introduction.- 3.2 Arsenides.- 3.3 Carbonates.- 3.4 Halides.- 3.5 Hydroxides.- 3.6 Native elements.- 3.7 Oxides.- 3.8 Phosphates.- 3.9 Sulphates.- 3.10 Sulphides.- 3.11 Tungstates.- 4 Transmitted-light crystallography.- 4.1 Introduction.- 4.2 Refraction.- 4.3 The refractive index.- 4.4 The Becke effect and the Becke line.- 4.5 Birefringence and Newton’s Scale of Interference Colours.- 4.5.1 Anomalous interference colours.- 4.6 Isotropic and anisotropic minerals.- 4.7 The isotropic indicatrix.- 4.8 The uniaxial indicatrix.- 4.8.1 Uniaxial crystals under crossed polars.- 4.8.2 Compensation and the determination of interference colour using the quartz wedge.- 4.8.3 The sensitive tint plate.- 4.8.4 Interference figures in uniaxial minerals and their sign.- 4.8.5 Determination of the mineral sign.- 4.9 The biaxial indicatrix.- 4.9.1 Interference figures in biaxial minerals.- 4.9.2 Determination of the sign in biaxial minerals.- 4.9.3 Determination of the extinction angle in biaxial minerals.- 4.10 Pleochroism.- 5 Reflected-light theory.- 5.1 Introduction.- 5.1.1 Reflectance.- 5.1.2 Indicating surfaces of reflectance.- 5.1.3 Observing the effects of crystallographic orientation on reflectance.- 5.1.4 Identification of minerals using reflectance measurements.- 5.2 Colour of minerals in PPL.- 5.2.1 CIE (1931) colour diagram.- 5.2.2 Exercise on quantitative colour values.- 5.3 Isotropic and anisotropic sections.- 5.3.1 Isotropic sections.- 5.3.2 Anisotropic sections.- 5.3.3 Polarization colours.- 5.3.4 Exercise on rotation on reflection.- 5.3.5 Detailed observation of anisotropy.- Appendix A Refractive indices.- A.1 Biaxial minerals.- A.2 Uniaxial positive minerals.- A.3 Uniaxial negative minerals.- A.4 Isotropic minerals.- Appendix B 2V size and sign of biaxial minerals.- Appendix C Properties of ore minerals.- Appendix D Mineral identification chart.- Appendix E Gangue minerals.