The Basic Copper Phosphate Minerals Pseudomalachite, Ludjibaite and Reichenbachite: An Infrared Emission and Raman Spectroscopic Study

Abstract

The molecular structures of the trimorphous basic copper phosphate minerals pseudomalachite, ludjibaite and reichenbachite have been studied using a combination of infrared emission spectroscopy and Raman spectroscopy. Infrared emission spectra have been obtained over the temperature range 100 to 1000 degrees Celsius. Infrared emission spectra of the three minerals are different, in line with differences in crystal structure and composition. IR emission spectra show that the minerals are completely dehydroxylated by 550 degrees Celsius. The thermal decomposition patterns for the three minerals are different and reflect their stability. Raman spectra are similar, particularly in the stretching region, but characteristic differences in the deformation regions are observed. Differences are also observed in the phosphate stretching and bending regions