Atoms, electrons, orbitals, and minerals -- The excited atom: spectra and quanta, ionization potential, electronegativity, and chemical bonding -- The crystal chemistry of the covalent bond -- The crystal chemistry of the ionic bond -- Pauling's second rule of electrostatic valency in ionic or coordination compounds -- External (nontranslational) and internal (translational) symmetry Crystal field theory -- Polyhedral distortion -- Diadochy and isostructural crystals -- Density, volume, unit cells, and packing -- Refractivity and polarizability.