EPMA, EPR, ELECTRONIC AND VIBRATIONAL SPECTRAL STUDIES ON NATURAL AURICHALCITE

The electron probe micro analysis (EPMA); electron paramagnetic resona nce (EPR), electronic and vibrational spectral studies on a natural mi neral, aurichalcite were studied at room temperature. The EPMA analysi s revealed the concentration of copper in the mineral to be 2.6 wt% an d zinc as 24.5 wt%. The optical spectra revealed the presence of coppe r in D-4h symmetry with crystal held (Dq) and tetragonal field (Ds and Dt) parameters as 1250, 1600 and 520cm(-1) respectively. This further confirmed the presence of Cu(II) ion in an elongated tetragonal site. The EPR studies indicated the presence of Cu(II) ion, but hyperfine l ines could hot be resolved due to the high concentration of the parama gnetic impurity in the mineral. The IR spectrum confirmed the presence of water and carbonate ion.