In situ Raman spectroscopic study of gypsum (CaSO4*2H2O) and Epsomite (MgSO4*7H2O) dehydration utilizing an ultrasonic levitator Posted on June 26, 2014 by UHNAI Webmaster in Brotton, S. J., R. I. Kaiser (). In situ Raman spectroscopic study of gypsum (CaSO4*2H2O) and Epsomite (MgSO4*7H2O) dehydration utilizing an ultrasonic levitator. , 4,