Grumiplucite, ideally HgBi 2 S 4 was identified at the Droždiak vein, Rudňany deposit (Spišsko-gemerské Rudohorie Mts., Slovakia). This rare Hg-sulfosalt forms metallic lead-grey to steel-grey, prismatic to acicular crystals up to 1 cm long, often grouped into irregular aggregates. It occurs in cavities of siderite with abundant cinnabar, Hg-rich tetrahedrite and chalcopyrite aggregates. Minor quartz or barite crystals and microscopic aggregates of Sb-rich bismuthinite to Birich antimonite were also observed. On the basis of chemical analyses, two types of grumiplucite were distinguished at the Rudňany deposit. The first is close to an ideal composition and has empirical formula Hg 0.99 Bi 1.94 S 4.08 (based on 7 apfu). The second is characterized by regularly elevated contents of Sb ranging from 0.02 to 0.77 apfu. Grumiplucite is monoclinic, space group C2/m, with unit-cell parameters refined from X-ray powder data: a = 14.172(2), b = 4.0525 (7), c = 13.975(1) Å, β = 118.257 (8) o and V = 707.0(2) Å 3 (Sb-free) and a = 14.183(1), b = 4.0538(5), c = 13.980(1) Å, β = 118.239 (1) o and V = 708.1(2) Å 3 (Sb-rich). Raman spectra for grumiplucite crystals with variable Sb contents are mutually well comparable. Therefore it seems that different Sb occupation does not affect the energy and intensity of Raman bands and they significantly differ from spectra of particularly structure-related mineral livingstonite, HgSb 4 S 8 . The dominant feature in the Raman spectra of grumiplucite is a series of spectral bands that corresponds to the stretching and bending vibrations of BiS 5 polyhedra and Hg-S bonds. Received: 23 July, 2015; accepted: 1 December, 2015; handling editor: F. Laufek 2013). This paper is focused on detailed mineralogical characterization of grumiplucite and associated minerals from the Rudňany deposit, Spišsko-gemerské Rudohorie Mts., Slovakia, which is a second world occurrence of this Hg-sulfosalt. We present here new wavelength-dispersive electron probe microanalyses, X-ray powder diffraction and Raman data for this very rare mineral phase.
Keywords: grumiplucite, sulfosalts, X-ray powder data, chemical composition, Raman spectroscopy, Rudňany deposit
Geological settingThe Rudňany deposit (or Rudňany ore field) is located c. 11 km SE of Spišská Nová Ves town in the northern part of Gemeric Superunit, Spišsko-gemerské Rudohorie Mts., Slovakia (Fig. 2); GPS coordinates of the Západ shaft are: 48°52'47.79"N and 20°39'29.98"E. It was one of the most important mining centers as well as the largest siderite-type (Fe-Ba-Cu-Hg) deposits in Slovakia, mined already in prehistoric times. Most of the mining activity ceased there in 1993; only minor mining of barite still continues at the Poráč shaft area to the present day.Hydrothermal siderite-quartz ± barite veins, sometimes with abundant sulfidic mineralization, strike W-E
