The internal compositional zoning of natural crystals provide a record of their growth process and history. Observation and interpretation of these patterns are fundamental to our knowledge of the Earth, providing crucial information to workers studying nearly every aspect of the Earth system. In this proposal, we seek to understand the conditions responsible for the crystallisation of the mineral zircon from silicate melts by imaging in three dimensions the fine-scale chemical (<1μm) oscillatory zonation, and relating this zonation to the common apatite inclusions found within zircon grains. These observations will form the basis for further numerical modelling experiments that will reconstruct the conditions of crystal growth, allowing us to correctly interpret the growth history and composition of zircon crystals. This proposal is ultimately motivated by the crucial role that the analysis of zircon plays in our understanding of earth history.