Tetrahedral site of Cu(II) in bornite and bournonite

Spectroscopic studies on two naturally occurring minerals bornite and bournonite are carried out by optical absorption and EPR techniques. In both samples doubly ionised copper ion exhibits in tetragonally distorted tetrahedral site symmetry. In the case of bornite triply ionised iron is in the regular tetrahedral site symmetry. Different crystal field and tetragonal parameters are evaluated: Dq = 450, B = 690 and C = 2600 cm(-1) for Fe(III) ion in Bornite Dq = 431, Ds = -642 and Dt = 462 cm(-1) for Cu(II) ion in Bornite Dq = 433, Ds = -639 and Dt = 468 cm(-1) for Cu(II) ion in Bournonite.