Rock-forming Minerals in Thin Section

Inhaltsverzeichnis

A Optical Crystallography.- 1 The polarizing microscope.- 1.1 Microscope components and their function.- 1.2 Accessory equipment.- 1.3 Adjustment of the microscope.- 1.3.1 Centring the condensing lens.- 1.3.2 Centring the objective.- 2 Orthoscopic observations.- 2.1 Observations with one polarizer.- 2.1.1 Light impervious (opaque) minerals and substances.- 2.1.2 Transparent minerals and substances.- 2.1.2.1 Characteristic crystal shapes.- 2.1.2.2 Cleavage.- 2.1.2.3 Colour and pleochroism.- 2.1.2.4 Refractive index: relief, chagrin, and the Becke line.- 2.2 Observations under crossed polars.- 2.2.1 Passage of light through isotropic media.- 2.2.2 Passage of light through anisotropic media.- 2.2.2.1 Birefringence and polarization.- 2.2.2.2 The indicatrix model.- 2.2.2.3 Optical character of elongation.- 2.2.2.4 Parallel, symmetric and oblique extinction.- 2.2.2.5 Twinning.- 3 Observations under conoscopic light.- 3.1 Introduction.- 3.2 Conoscopic examination of optically uniaxial crystals.- 3.2.1 Conoscopic images of uniaxial crystals in different orientations.- 3.2.2 Determination of the optical character of uniaxial crystals.- 3.3 Determination of the optical character of biaxial minerals in the conoscopic light path.- 3.3.1 Conoscopic images of biaxial minerals in different orientations.- 3.3.2 Identification of the optical character of biaxial crystals.- 3.3.3 Estimation of the optic axial angle 2V.- 3.3.4 Determination of optic axial angles 2V in oblique section.- Summary 1: Mineral identification with the polarizing microscope.- Summary 2: Protocol of mineral identification in thin section.- B Optical Mineralogy.- 1 Opaque minerals and substances.- 1.1 Magnetite.- 1.2 Ilmenite.- 1.3 Hematite.- 1.4 Pyrite.- 1.5 Pyrrhotite.- 1.6 Graphite.- 1.7 Carbonaceous substances.- 2 Optically isotropic (also pseudocubic) minerals and amorphous substances.- 2.1 Perovskite.- 2.2 Spinel group.- 2.3 Pyrochlore and koppite.- 2.4 Garnet group.- 2.4.1 Pyrope.- 2.4.2 Almandine.- 2.4.3 Grossularite.- 2.4.4 Melanite.- 2.5 Leucite.- 2.6 Sodalite group.- 2.7 Analcite.- 2.8 Cristobalite.- 2.9 Fluorite.- 2.10 Amorphous minerals, glass and cryptocrystalline material.- 2.10.1 Limonite.- 2.10.2 Opal.- 2.10.3 Rock-glass.- 3 Optically uniaxial minerals.- 3.1 Minerals which are optically uniaxial positive.- 3.1.1 Rutile.- 3.1.2 Cassiterite.- 3.1.3 Zircon.- 3.1.4 Xenotime.- 3.1.5 Melilite group.- 3.1.6 SiO2 group.- 3.1.6.1 Quartz.- 3.1.6.2 Chalcedony.- 3.1.6.3 Tridymite.- 3.1.7 Chabazite.- 3.2 Minerals with uniaxial negative character.- 3.2.1 Anatase.- 3.2.2 Trigonal carbonate group.- 3.2.2.1 Calcite.- 3.2.2.2 Dolomite.- 3.2.2.3 Magnesite.- 3.2.2.4 Siderite.- 3.2.3 Corundum.- 3.2.4 Vesuvianite.- 3.2.5 Tourmaline.- 3.2.6 Apatite.- 3.2.7 Beryl.- 3.2.8 Nepheline.- 3.2.9 Scapolite group.- 3.2.10 Apophyllite.- 3.2.11 Cancrinite.- 4 Biaxial crystals.- 4.1 Olivine group.- 4.2 Pyroxene group.- 4.2.1 Orthopyroxene group: enstatite, bronzite, hypersthene.- 4.2.2 Clinopyroxenes.- 4.2.2.1 Diopside group.- 4.2.2.2 Augite group.- 4.2.2.3 Titanaugite.- 4.2.2.4 Pigeonite.- 4.2.2.5 Aegirine-augite series.- 4.2.2.6 Jadeite.- 4.2.2.7 Omphacite.- Determination of the maximum extinction angle for pyroxenes and amphiboles.- 4.3 Amphibole group.- 4.3.1 Actinolite group.- 4.3.2 Green ('common') hornblende.- 4.3.3 Brown hornblende.- 4.3.4 Glaucophane and crossite.- 4.3.5 Arfvedsonite and riebeckite.- 4.4 Mica group.- 4.4.1 Muscovite.- 4.4.2 Phengite.- 4.4.3 Lithionite series.- 4.4.3.1 Lepidolite.- 4.4.3.2 Zinnwaldite.- 4.4.4 Biotite series.- 4.4.4.1 Phlogopite.- 4.4.4.2 Biotite s.s..- 4.4.5 Oxybiotite.- 4.4.6 Titanbiotite.- 4.5 Stilpnomelane.- 4.6 Glauconite and celadonite.- 4.7 Talc.- 4.8 Chlorite group.- 4.8.1 Orthochlorite.- 4.8.2 Leptochlorite.- 4.9 Serpentine group.- 4.9.1 Antigorite.- 4.9.2 Chrysotile.- 4.10 Feldspar family.- 4.10.1 Alkali feldspars.- 4.10.1.1 Sanidine.- 4.10.1.2 Orthoclase.- 4.10.1.3 Anorthoclase.- 4.10.1.4 Microcline.- 4.10.2 Plagioclase series.- 4.11 Zeolite family.- 4.11.1 Fibrous zeolites.- 4.11.1.1 Natrolite.- 4.11.1.2 Mesolite.- 4.11.1.3 Thomsonite.- 4.11.1.4 Scolecite.- 4.11.1.5 Mordenite.- 4.11.1.6 Laumontite.- 4.11.2 Flaky zeolites.- 4.11.2.1 Heulandite.- 4.11.2.2 Stilbite.- 4.11.2.3 Epistilbite.- 4.11.3 Cubic zeolites.- 4.11.3.1 Phillipsite.- 4.11.3.2 Harmotome.- 4.12 Aenigmatite (cossyrite).- 4.13 Sphene (titanite).- 4.14 Topaz.- 4.15 Cordierite.- 4.16 Al2SiO5 group.- 4.16.1 Andalusite.- 4.16.2 Sillimanite.- 4.16.3 Kyanite.- 4.17 Staurolite.- 4.18 Wollastonite.- 4.19 Chloritoid.- 4.20 Epidote zoisite group.- 4.20.1 Zoisite.- 4.20.2 Epidote.- 4.20.3 Clinozoisite.- 4.20.4 Orthite (allanite).- 4.21 Pumpellyite.- 4.22 Lawsonite.- 4.23 Anhydrite.- 4.24 Gypsum.- 4.25 Aragonite.- 4.26 Barite.- 4.27 Goethite.- 4.28 Prehnite.- C Appendices.- 1 Tables for the microscopic identification of rock-forming minerals.- 2 Diagrams for the classification of magmatic rocks.- 3 Diagrams of mineral and rock structures.