Original paper

Zdenekite, NaPbCu5(AsO4)4Cl.5H2O, a new mineral from the Cap Garonne mine, Var, France

Chiappero, Pierre-Jacques; Sarp, Halil

European Journal of Mineralogy Volume 7 Number 3 (1995), p. 553 - 558

11 references

published: May 19, 1995
manuscript accepted: Dec 21, 1994
manuscript received: Jul 7, 1994

DOI: 10.1127/ejm/7/3/0553

BibTeX file

ArtNo. ESP147050703009, Price: 29.00 €

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Abstract

Abstract : Zdenekite occurs as single tetragonal tabular crystals (up to 0.1 mm) flattened on {001}, or as spherulites and aggregates up to 0.3 mm across. The crystal forms observed are {001}, {100} and {110}. The mineral is fragile and soft, has an irregular fracture and a perfect cleavage along (001). Megascopically, the mineral is translucent with a vitreous lustre and an intense blue colour with a pale blue streak. It is not fluorescent in the ultra-violet range. Zdenekite is optically uniaxial negative; ω = 1.770(5), 8 = 1.710(5), measured at 590 nm; it is pleochroic with O = intense turquoise blue and E = pale blue to light green. The measured specific gravity is 4.1(1) g/cm3. Zdenekite is tetragonal, possible space groups P4122 or P4322, unit-cell parameters a = 10.066(1), c = 39.39(4) Å, V = 3991.41(4) Å3, Z = 8, Dcalc = 4.08 g/cm3. The strongest lines in the powder pattern are [I, d(Å), (hkl)]: 100, 9.83, (004); 60, 4.925, (008); 50, 4.482, (204) (211); 90, 3.132, (226) (1.0.12); 40, 2.772, (308) (317); 50, 2.515, (400) (401); 40, 1.778, (440) (441). The average of 16 electron-microprobe analyses gave (in wt%): Na2O 2.92; CaO 0.62; PbO 16.79; CuO 32.97; As2O5 36.66; Cl 3.54; H2O (by TGA) 7.2; Cl = 0 - 0.80; total 99.90. The empirical formula calculated on the basis of 22(O + Cl) is Na1.15Ca0.13Pb0.92Cu5.09As3.90H9.82Cl1.23O20.77, or ideally NaPbCu5(AsO4)4Cl.5H2O. Zdenekite is the tetragonal lead analogue of lavendulan. It was found in the northern part of the Cap Garonne mine. It is associated with anglesite, an unknown mineral of the tsumcorite group, and olivenite in a quartz conglomerate mineralized in tennantite and covellite. The name honours Dr Zdenek Johan (1935-), mineralogist and Director of Scientific Affairs of the Bureau de Recherches Géologiques et Minières (BRGM), France

Keywords

zdenekitenew mineralsodium copper lead arsenateCap GaronneFrance.