We report preliminary petrographic and mineral chemical data for a rock hosting an unusual mineral assemblage from Långban, Värmland, Sweden. The rock is a two feldspar-scapolite-spessartine-romeite skarn. The bulk composition and high degree of enrichment in Pb, Sb and As suggest that the rock was formed by reaction between a pre-existing Mn skarn containing the chalcophiles and a potassic granite, with loss of silica, alkalis and CO2. The alkali feldspar is a Pb-rich hyalophane, averaging Or63Ab19Cs15Pb03, the plagioclase feldspar a Pb-rich labradorite, An48Ab48Or02Pb02, and the scapolite a 'mizzonite' (Ca/(Na+Ca) = 0.66—0.70). These minerals show their highest Pb contents recorded in nature to date: up to a maximum of 5.7 wt.% PbO in the hyalophane, 2.1% PbO in the plagioclase, and 5.3% PbO in the scapolite. Laser ablation ICP-MS of a scapolite grain detected substantial Be up to 1.7 wt.% BeO (0.6 Be per 12 tetrahedral cations), as well as Pb up to 7.05 wt.% PbO. The Be is incorporated into scapolite via the coupled exchange [Be(OH)][Al(CO3,SO4)]—1. This is the first documentation of scapolite as the major repository for Be in a rock.The romeite also contains substantial Pb, and shows extensive solid solution towards end-members containing Fe3+, Ti and Sb3+. In some analyses, the dominant end-members are and its Pb analogue rather than (Ca,Pb)2Sb2O7. Complex exsolution textures are displayed in the hyalophane, by hancockite-epidote, romeite-bindheimite and hedyphane-johnbaumite. Ca-rich scapolite and hancockite appear to be new minerals for the Långban deposit.The mineralogy appears consistent with the regional peak conditions of P = 3 kbar, T > 600°C. Several potential thermobarometers for Mn-rich skarns are identified in this rock.

More than 40 recently discovered tourmaline

AND KJELL GATEDALXenos Mineral, Ra Ê gvägen 7, SE-713 34 Nora, Sweden ABSTR ACTThe La Ê ngban, Nordmark and Jakobsberg Mn-Fe deposits contain the only known occurrences of filipstadite and manganostibite (ideal formulae (Mn, Mg) 2 (Sb 5+ 0.5 Fe 3+ 0.5 )O 4 and Mn 2+ 7 SbAsO 12 , respectively). Filipstadite from Nordmark is newly recognized, and occurs in assemblages with svabite-johnbaumite, calcite, tephroite-forsterite, phlogopite-kinoshit alite, tilasite, +jacobsite, +plumb-ian roméite, +adelite, +hedyphane. Manganostibite from La Ê ngban and Jakobsberg is reported for the first time, and the mineral is generally associated with katoptrite, tephroite, humite-group minerals, calcite, svabite, allactite, manganosite, hausmannite, jacobsite, spinel s.s., etc. Whereas filipstadite is clearly secondary relative to the major part of the matrix components, manganostibite is believed to have formed coevally with the principal ore and skarn minerals at these deposits.The previously known compositional ranges are extended. Based on electron-microprobe analyses, Nordmark filipstadite contains 4.1 7.3 MgO, 0.0 0.5 Al 2 O 3 , 30.5 45.3 MnO, 17.0 40.1 Fe 2 O 3 , 0.2 0.9 ZnO, 19.9 29.9 Sb 2 O 5 (all in wt.%), corresponding to 58 100 mol.% of a pure filipstadite component. Associated jacobsites show Sb 2 O 5 contents of up to c. 5 wt.%. Manganostibites (all three deposits considered) contain 1.0 2.9 MgO, 2.8 3.8 SiO 2 , 57.4 60.3 MnO, 0.2 3.5 Mn 2 O 3 , 0.3 2.0 Fe 2 O 3 , 0.0 2.4 ZnO, 21.5 23.0 Sb 2 O 5 , 7.7 10.0 As 2 O 5 (all in wt.%).Si and trivalent cations are incorporated via a (Mn 3+ ,Fe 3+ ) + Si 4+ = Mn 2+ + As 5+ exchange mechanism, which improves the local charge-balance at tetrahedral structural sites dominated by As.

Rinmanite, ideally Zn 2 Sb 2 Mg 2 Fe 4 O 14 (OH) 2 , is a new mineral species from the Garpenberg Norra Zn-Pb mine, Hedemora, Dalarna, in south-central Sweden, where it occurs in a skarn assemblage associated with tremolite, manganocummingtonite, talc, franklinite, barite and svabite. Rinmanite crystals are prismatic, up to 0.5 mm in length, with good {100} cleavage. The VHN 100 is in the range 841-907. D calc = 5.13(1) g•cm-3. The mineral is black (translucent dark red in thin splinters) with a submetallic luster. The mineral is moderately anisotropic and optically uniaxial (-). Reflectance values measured in air are 13.5-12.1% (= 470 nm), 12.9-11.8% (546 nm), 12.6-11.7 (589 nm) and 12.2-11.3% (650 nm). Electron-microprobe analyses of rinmanite (wt.%) gave MgO 8.97, Al 2 O 3 0.82, MnO 2.47, Fe 2 O 3 34.33, ZnO 14.24, Sb 2 O 5 36.31, H 2 O 1.99 (calculated), sum 99.13, yielding the empirical formula (Zn 1.58 Mn 0.31 Mg 0.06) ⌺1.95 Sb 2.03 [Mg 1.95 Fe 3.88 Al 0.15 ] ⌺5.98 O 14.01 (OH) 1.99. Rinmanite is hexagonal, space group P6 3 mc, with a 5.9889(4), c 9.353(1) Å, V 290.53(5) Å 3 and Z = 1. A structure refinement from single-crystal MoK␣ X-raydiffraction data (R = 3.1% for 199 reflections) shows that rinmanite is isostructural with nolanite. The octahedral M(1) and M(2) sites are occupied by (Mg + Fe) and Sb, respectively, whereas Zn is located at the 4-coordinated M(3) site. The strongest eight lines in the powder-diffraction pattern [d in Å (I obs)(hkl)] are: 5.19(20)(100), 3.47(34)(102), 2.99(43)(110), 2.67(44)(103), 2.522(100)(112), 1.660(28)(213), 1.517(33)(205) and 1.497(54)(220). Mössbauer spectroscopy confirms that rinmanite contains Fe 3+ at octahedral sites and is in a paramagnetic state down to at least 77 K. Rinmanite is believed to have formed during prograde metamorphism of an initially lowS , siliceous carbonate protolith enriched in Zn, Sb and Fe, at relatively high P(H 2 O). The new mineral species is named after Sven Rinman (1720-1792), of Bergskollegium.

Due to its strong chalcophile character and the influence of its s(2) lone-pair electrons on the crystal structure trivalent bismuth is extremely rare in silicate minerals, with Bi-contents in common silicates typically below 1 ppm. In the present paper, we report on an exceptionally Bi-rich variety of the rock-forming mineral vesuvianite with up to ca. 20 wt% Bi2O3, occasionally in combination with enhanced Pb contents up to ca. 5 wt% PbO. The mineral occurs as small (<= 300 mu m) idiomorphic, black crystals in a sulfide-free silicate skarn in the Langban Mn-Fe deposit, central Sweden. The major skarn minerals comprise Ba-rich potassium feldspar, albitic plagioclase, Pb-rich scapolite, and phlogopite, while Pb-rich epidote, vesuvianite, and calcic garnets are minor phases. The vesuvianite grains are intensely zoned displaying Bi-rich cores surrounded by thinner Bi-poor rims. Although generally high in bismuth, the crystal cores invariably show oscillatory zoning. In addition to high Bi- and Pb-contents, the crystals are occasionally enriched in copper, cerium, antimony, and arsenic, thus reflecting the complex chemistry and evolution of the Langban mineralization. Chemical analyses demonstrate a strong negative correlation between Ca and Bi, hence confirming that Bi replaces Ca at X sites of the vesuvianite structure. Concentrations of Si and Al are lower, while Fe and Ti contents are somewhat enhanced in the Bi-rich cores. Maximum Bi and Pb contents analyzed in the present vesuvianite crystals correspond to 3.19 and 0.87 atoms per formula unit, respectively. This exceeds by far previous reports in the literature. X-ray single-crystal diffraction studies of a crystal splinter with intermediate Bi-content (1.08 apfu) show that the space group P4/nnc is the most appropriate to describe the crystal structure; the refinement converged to an R1 index of 0.0493. The recorded unit-cell parameters, a = 15.7018(6), c = 11.8648(6) angstrom, and V = 2925.2(2) angstrom(3), are to our knowledge the largest ones observed so far for P4/nnc vesuvianite. Bismuth was demonstrated to order at the X3'(Bi) site that is only 0.46 angstrom distant from the nearest X3(Ca) site. Consequently, the X3 and X3' sites cannot be simultaneously fully occupied