High-pressure electrical conductivity and Raman spectroscopy of chalcanthite

The phase transitions and dehydration of chalcanthite were investigated by electrical conductivity and Raman spectroscopy at 1.0-24.0 GPa and 293-673 K in a diamond anvil cell. At ambient temperature, two secondary phase transitions were observed according to discontinuous changes in the slope of Raman shifts, full width at half maximum and electrical conductivities at similar to 7.3 and similar to 10.3 GPa. The dehydration temperatures were determined by the splitting of Raman peaks and changes in electrical conductivity as similar to 350 and similar to 500 K at respective similar to 3.0 and similar to 6.0 GPa. A positive relationship for chalcanthite between dehydration temperature and pressure is established.