Crystals and the Polarising Microscope: A Handbook for Chemists and Others

acute bisectrix anisotropic axes Bertrand lens biaxial crystals birefringence bisectrix calcite centre chloride circular section cleavage coincide compounds condenser cone convergent light cover slip cross-wires crossed Nicols crystal plate crystallisation crystallographic cubic determined diaphragm dispersion double refraction ellipsoid elliptic elongation examination example extinction position extraordinary ray eyepiece faces focussing given glass goniometer hexagonal indicatrix indices interference figure iris diaphragm isogyres isotropic lattice liquid melatopes method molecules monoclinic mounted Nicol prism normal objective ocular optic axial angle optic axial plane optic axis optical properties optically active ordinary ray orientation orthorhombic perpendicular pinacoid pleochroism polarisation colours polarised light polarising microscope potassium principal section prism rays travel refractive index rhombohedron right angles rotation shown in Fig slide sodium solution stage substance tangent tetragonal thickness tion triclinic trigonal tube twinning uniaxial crystals velocity vertical vibration directions vibration planes wave front wave surface wave-length