9 QUARTZ PIEZOELECTRIC CRYSTALS, SEMIFINISHED QUARTZ PIEZOELECTRIC CRYSTAL BLANKS, ELECTRODE-CONTAINING HOLDERS FOR UTILIZING PIEZOELECTRIC CRYSTALS IN ELECTRICAL CIRCUITS, UNITS CONSISTING OF QUARTZ PIEZOELECTRIC CRYSTALS MOUNTED IN ELECTRODE-CONTAINING HOLDERS THEREFOR, ELECTRICALLY HEATED THERMOSTATICALLY CONTROLLED OVENS CONTAINING ELECTRODES FOR UTILIZING QUARTZ PIEZOELECTRIC CRYSTALS IN ELECTRICAL OIRCUITS, UNITS CONSISTING OF QUARTZ PIEZOELECTRIC CRYSTALS MOUNTED IN ELECTRICALLY HEATED TEMPERATURE-CONTROLLED OVENS