Growth hystory of a quartz crystal from growth marks and fluid inclusions data

The optical study of a quartz crystal from the skarn-sulfide deposit at Valle del Temperino (Italy) revealed four main growth zones, and suggested that significant changes in the growth environment occurred between the first two and the last two zones. In fact, fluid inclusions record a decrease of mean homogenization temperature and (to a lesser extent) of salinity from the first two zones (Th = 234-degrees-C, salinity = 1.0 wt.% NaCl equiv.) to the last two zones (Th = 218-degrees-C, salinity = 0.7 wt.% NaCl equiv.). Therefore, the changes in the growth of the crystal reflect cooling and dilution of the mineralizing fluids.