TY - JOUR

T1 - Jasrouxite, a new Pb-Ag-As-Sb member of the lillianite homologous series from Jas Roux, Hautes Alpes, France

AU - Topa, Dan

AU - Makovicky, Emil

AU - Favreau, Georges

AU - Bourgoin, Vincent

AU - Boulliard, Jean-Claude

AU - Zagler, Georg

AU - Putz, Hubert

PY - 2013

Y1 - 2013

N2 - The thallium-rich sulfosalt deposit of Jas Roux, situated in the Pelvoux Massif (Hautes-Alpes de´partement, France), occurs in a Triassic sedimentary series. Jasrouxite belongs to the early lead-containing stages of the Tl–As–Sb period of mineralization. It occurs in a silicified gangue, along with smithite and late realgar. Jarouxite forms dark gray anhedral grains with metallic luster, up toseveral millimeters in size, as well as aggregates of grains which range to more than 10 mm in diameter. From their surface, grains of jasrouxite are embayed by a three-phase myrmekite aggregate composed of stibnite, boscardinite and smithite. The mineral is brittle, with irregular fracture; no cleavage or parting was observed. In reflected light, color is off-white. Bireflectance is weak, in off-white tones; anisotropy is distinct. Rare straight twin lamellae occur in otherwise untwinned crystals. The empirical formula, on the basis of 132 apfu derived from the crystal-structure determination, is Cu0.79Ag14.64Pb4.10Tl0.05As15.37Sb24.87S72.18. Calculated density is4.87 g.cm3. The simplified formula is Ag16Pb4(Sb25As15)40S72; the only notable variation is the partial substitution As$Sb.Jasrouxite is triclinic, space group P-1. Lattice parameters are a 8.2917(5) A ° , b 19.101(1) A ° , c 19.487(1) A ° , a 89.731(1), b 83.446(1), g 89.944(1), V 3066.1(3) A ° 3, Z ¼ 1 for Ag16Pb4(Sb24As16)40S72.Jasrouxite is a member of the lillianite homologous series, its order number is 4 and degree of Ag þ (Sb, As)$2 Pb substitution is 36.5 % above the theoretical 100 % substitution expressed as PbAg(Sb,As)3S6. The most important features of the crystal structure are: substantial replacement of lead in selected trigonal prismatic sites by Sb, formation of a string of large volumes for accommodationof lone electrons of Sb and As in the central portions of galena-like slabs, and high contents of Ag and (Sb,As).

AB - The thallium-rich sulfosalt deposit of Jas Roux, situated in the Pelvoux Massif (Hautes-Alpes de´partement, France), occurs in a Triassic sedimentary series. Jasrouxite belongs to the early lead-containing stages of the Tl–As–Sb period of mineralization. It occurs in a silicified gangue, along with smithite and late realgar. Jarouxite forms dark gray anhedral grains with metallic luster, up toseveral millimeters in size, as well as aggregates of grains which range to more than 10 mm in diameter. From their surface, grains of jasrouxite are embayed by a three-phase myrmekite aggregate composed of stibnite, boscardinite and smithite. The mineral is brittle, with irregular fracture; no cleavage or parting was observed. In reflected light, color is off-white. Bireflectance is weak, in off-white tones; anisotropy is distinct. Rare straight twin lamellae occur in otherwise untwinned crystals. The empirical formula, on the basis of 132 apfu derived from the crystal-structure determination, is Cu0.79Ag14.64Pb4.10Tl0.05As15.37Sb24.87S72.18. Calculated density is4.87 g.cm3. The simplified formula is Ag16Pb4(Sb25As15)40S72; the only notable variation is the partial substitution As$Sb.Jasrouxite is triclinic, space group P-1. Lattice parameters are a 8.2917(5) A ° , b 19.101(1) A ° , c 19.487(1) A ° , a 89.731(1), b 83.446(1), g 89.944(1), V 3066.1(3) A ° 3, Z ¼ 1 for Ag16Pb4(Sb24As16)40S72.Jasrouxite is a member of the lillianite homologous series, its order number is 4 and degree of Ag þ (Sb, As)$2 Pb substitution is 36.5 % above the theoretical 100 % substitution expressed as PbAg(Sb,As)3S6. The most important features of the crystal structure are: substantial replacement of lead in selected trigonal prismatic sites by Sb, formation of a string of large volumes for accommodationof lone electrons of Sb and As in the central portions of galena-like slabs, and high contents of Ag and (Sb,As).

U2 - 10.1127/0935-1221/2013/0025-2336

DO - 10.1127/0935-1221/2013/0025-2336

M3 - Journal article

VL - 25

SP - 1031

EP - 1038

JO - European Journal of Mineralogy

JF - European Journal of Mineralogy

SN - 0935-1221

ER -