Abstract
Pentlandite, niccolite and gersdorffite from the Han Deresi and Günes districts, eastern Turkey, were described. The specific gravity and the cell constants of each of these specimens were measured, and it was confirmed that these physical data were in good agreement with those given in literatures. It was also concluded that the specimen of gersdorffite under investigation was of the ordered structure with the space group, P213-T4. Chemical analyses of these specimens were carried out both by the usual wet method and with a electron microprobe. The results indicated that, when gersdorffite and niccolite co-exist, Sb seems to prefer entering into gersdorffite to going into niccolite. The stability field of gesdorffite was discussed and it was inferred that the presence of Fe in place of Ni might widen the stability field of the ordered form.
