1529-6466/03/0053-0015$05.00 15 Spectroscopic methods applied to zircon Lutz Nasdala Institut für Geowissenschaften – Mineralogie Johannes Gutenberg-Universität Mainz D-55099 Mainz, Germany Ming Zhang Department of Earth Sciences, University of Cambridge Downing Street, Cambridge CB2 3EQ, United Kingdom Ulf Kempe Institut für Mineralogie Technische Universität Bergakademie Freiberg Brennhausgasse 14,D-09596 Freiberg, Germany Gérard Panczer Laboratoire de Physico-Chimie des matériaux Luminescents, UMR 5620 CNRS Université Claude Bernard – Lyon 1 69622 Villeurbanne, France Michael Gaft International Technologies Laser Rishon-Lezion 75140, Israel Michael Andrut Institut für Mineralogie und Kristallographie Universität Wien – Geozentrum A-1090 Wien, Austria Michael Plötze Institut für Geotechnik Eidgenössische Technische Hochschule Zürich CH-8093 Zürich, Switzerland INTRODUCTION Natural and synthetic (pure and doped) zircon (ZrSiO 4 ) have been studied with a variety of spectroscopic techniques. These techniques are based on different physical phenomena, for in- stance transitions between spin states of nuclei and electrons, energetic transitions of valence electrons, intra-molecular vibrations, or vibrations of atoms and molecular units in the lattice. All of the diverse spectroscopic techniques, however, have in common that they probe energy differences between a ground and excited states, mostly upon interaction of the mineral with incident radiation. Such interactions are not only determined by the excited elementary particles or molecules them- selves but depend greatly on their local environments (i.e. number, type, valence and geometrical arrangement of neighboring atoms). Spectroscopic techniques are thus sensitive to the local struc- ture and provide information on the short-range order. Most research on zircon crystals using spectroscopic techniques was done to study their “real structures,” that is the characterization of deviations from “perfect” zircon. Such features include