VISUAL SIMULATION OF CRYSTAL GROWTH AND DEVELOPMENT OF SECTOR ZONING IN HYDROTHERMAL QUARTZ

Crystal growth in the natural environment is a poorly understood process. Recent measurements of chemical impurities preserved within natural crystals offer important clues toward understanding morphologic evolution during crystal growth. In natural hydrothermal quartz crystals, internal chemical heterogeneities define sector zones as individual growth faces trap different amounts of impurities. The concentration of impurities is a sensitive indicator of the kinetics of crystal growth and thus can serve as a speedometer of the growth rate of individual faces. We present a visual simulation that illustrates the morphologic evolution of a quartz crystal as it grows from hydrothermal solution. We show how growth on different crystal faces leads to chemically distinguishable sector zones inside a single crystal. Our simulations can generate the large differences in impurity concentrations across sharp sector zone boundaries that are observed in natural crystals. Our results constrain the relative growth rates of individual faces during crystal growth in the hydrothermal environment.