New data on gersdorffite and associated minerals from the Peloritani Mountains (Sicily, Italy)

Abstract

Abstract. Gersdorffite, ideally NiAsS, and associated minerals from Contrada Zillì (Peloritani Mountains, Sicily, Italy) have been characterized through electron microprobe analysis and X-ray diffraction. Primary minerals, hosted in quartz veins, are represented by gersdorffite, tetrahedrite-(Fe), and chalcopyrite with minor pyrite and galena. Rare aikinite inclusions were observed in tetrahedrite-(Fe) and chalcopyrite. Gersdorffite occurs as euhedral to subhedral crystals, up to 1 mm in size, with (Sb,Bi)-enriched cores and (Fe,As)-enriched rims. Its chemical composition is (Ni0.79−0.95Fe0.18−0.04Co0.04−0.01)(As0.90−1.03Sb0.10−0.00Bi0.02−0.00)S0.98−0.92. It crystallizes in the space group P213, with unit-cell parameters a=5.6968(7) Å, V=184.88(7) Å3, and Z=4, and its crystal structure was refined down to R1= 0.035. Associated tetrahedrite-(Fe) has chemical formula (Cu5.79Ag0.07)Σ5.86(Cu3.96Fe1.59Zn0.45)Σ6.00(Sb3.95As0.17Bi0.03)Σ4.15S13.06, with unit-cell parameters a= 10.3815(10) Å, V=1118.9(3) Å3, and space group I-43m. Its crystal structure was refined to R1=0.027. Textural and crystallographic data suggest a polyphasic crystallization of gersdorffite under low-temperature conditions.

Tetrahedrite-(Ni), Cu6(Cu4Ni2)Sb4S13, the first nickel member of tetrahedrite group mineral from Luobusa chromite deposits, Tibet, China

“…Because the ionic radius of which seems like a common phenomenon in the tetrahedrite group minerals (Biagioni et al 2020bMauro et al 2021;Sejkora et al 2021Sejkora et al , 2022. As Biagioni et al…”

Mineralogy and geochemistry of Cu-Ni±Co±Ag±Bi polymetallic ores from the Hintermühlergang vein in the Chełmiec deposit, Sudetes Mountains, Poland

“…The char ac ter is tic fea ture of gersdorffite II from Che³miec is its zonation, vis i ble in BSE im ages. Os cil la tory zonation in sulpharsenides is known from many hy dro ther mal de pos its world wide (Fanlo et al, 2004;Kiefer et al, 2017;Mauro et al, 2021;Mederski et al, 2021). The zonation is usu ally caused by As«S sub sti tu tion which may be com bined with vari able chem is try at the Ni-Co-Fe cationic po si tion, which may be re lated to microenvironments and spa tially re stricted in flux of the re duc ing agents re spon si ble for the min er al iza tion (Scharrer et al, 2019).…”

Occurrence and crystal chemistry of austinite, conichalcite and zincolivenite from the Peloritani Mountains, northeastern Sicily, Italy

“…In this respect, a better knowledge of the mineralogy of these deposits is mandatory. Among primary minerals, arsenopyrite and gersdorffite are known to occur (Donati et al , 1978; Triscari and Saccà, 1982; Triscari, 1985; Mauro et al , 2021) and minor As occurs in Pb/Sb sulfosalts (e.g. Triscari and Saccà, 1984) and tetrahedrite-group minerals (Mauro et al , 2021).…”

“…Among primary minerals, arsenopyrite and gersdorffite are known to occur (Donati et al , 1978; Triscari and Saccà, 1982; Triscari, 1985; Mauro et al , 2021) and minor As occurs in Pb/Sb sulfosalts (e.g. Triscari and Saccà, 1984) and tetrahedrite-group minerals (Mauro et al , 2021). The alteration of these species gives rise to the occurrence of supergene arsenates.…”