Prof Ben Williamson
As part of my research on airborne particulate, I was involved in a study to determine the nature and formation of cristobalite in lavas from the Soufrière Hills volcano, Montserrat, in collaboration with researchers from the University of Durham, Natural History Museum, and Brighton and Sussex Medical School, published in Bulletin of Volcanology 2013. Cristobalite (a mineral with the same chemistry as quartz but a different crystal structure) was found to have crystallised from volcanic glass and as precipitates from vapours to fill pores within the lava structure. This could help strengthen the lava so making it less likely to collapse to produce a pyroclastic flow. However, conversely, by blocking pores its presence could cause pressure build up inside the volcano increasing the likelihood of dome collapse. Moreover, the inhalation of volcanic ash containing cristobalite is potentially hazardous to human health, as explained in a previous paper by the same team published in Particle and Fibre Toxicology 2012. More information on the mechanisms of eruption of the Soufrière Hills volcano has also been published in Earth and Planetary Science Letters 2010.
Scanning electron photomicrograph of a cristobalite crystal within a vesicle in volcanic rock from Montserrat (field of view 0.05 mm).