In collaboration with Drs. Alain Burgisser and Ian Schipper of the CNRS-ISTO, we are applying 3D Xray microtomography to image the structure of experimentally produced rhyolite pumices and constrain bubble coalescence mechanisms. Our measurements have yielded accurate, high-resolution reconstructions that capture bubble-bubble interactions in expanding vesicular rhyolite melts. In collaboration with Drs. Alain Burgisser and Ian Schipper of the CNRS-ISTO, we are applying 3D Xray microtomography to image the structure of experimentally produced rhyolite pumices and constrain bubble coalescence mechanisms. Our measurements have yielded accurate, high-resolution reconstructions that capture bubble-bubble interactions in expanding vesicular rhyolite melts.