Exploratory studies of the solubility of minor elements in tetrahedrite. VI. Zinc and the combined zinc-mercury and iron-mercury substitutions
Karup-Mø ller, Sven; Makovicky, Emil
published: Nov 29, 2004
Twenty-six tetrahedrite charges were weighed out in the system Cu12 Sb4 S13 Cu14 Sb4 S13 Cu10 Zn2 Sb4 S13, analysed by means of electron microprobe and their a parameter was determined by X-ray diffraction using a GuinierHÄgg camera. For Cu-poor tetrahedrite a(Å) = 0.0293 Zn (p. f. u.) + 10.324 and for Cu-rich tetrahedrite a (Å) = 0.0319 Zn (p. f. u.) + 10.448. Up to ~ 0.6 Zn atoms p. f. u., low-temperature exsolution into Cu-poor and Cu-rich tetrahedrite takes place. Twenty-one charges that combine Zn and Hg substitution and several orientational charges with Fe Hg substitution confirm the miscibility of these elements in tetrahedral sites of the structure and the linearity of unit cell parameter changes caused by these substitutions.