Manuelarossiite, ideally CaPbAlF7, is a new fluoride mineral found in a specimen from a fumarole formed subsequent to the 1944 eruption of the Vesuvius volcano, Naples Province, Campania, Italy. It occurs as very rare tabular crystals, up to 0.06 × 0.04 × 0.015 mm, in the vugs of volcanic scoria, associated with cerussite. In the same scoria where manuelarossiite was found, anglesite, artroeite, atacamite, calcioaravaipaite, cerussite, challacolloite, cotunnite, hephaistosite, matlockite, napoliite and susannite were identified. Manuelarossiite is colourless with a white streak and adamantine lustre. It is brittle and has a laminated fracture. Cleavage is perfect on {001}. Dcalc = 5.095 g cm–3. The calculated mean refractive index is 1.625. The chemical composition (wt.%, electron microprobe, H2O calculated by stoichiometry) is: CaO 13.98, PbO 55.46, Al2O3 12.59, F 29.45, H2O 1.68, –O=F –12.40, total 100.76. The empirical formula calculated on the basis of 7 anions is Ca1.00Pb1.00Al1.00[F6.25(OH)0.75]Σ7.00. Raman spectroscopy confirms the limited presence of OH– groups in the mineral. Manuelarossiite is monoclinic, space group C2/m, with a = 7.6754(3), b = 7.4443(4), c = 9.2870(5) Å, β = 93.928(5)°, V = 529.39(5) Å3 and Z = 4. The strongest lines of the powder X-ray diffraction pattern [d, Å (I, %) (hkl)] are: 9.257 (57) (001); 4.537 (72) (111); 3.725 (98) (020); 3.630 (57) (20$\bar 1$); 3.588 (65) (11$\bar 2$); 3.460 (100) (021); 3.422 (63) (112); and 2.673 (65) (220). The crystal structure was refined to R1 = 0.056 for 849 reflections with F > 4σ(F). It is characterised by {001} layers formed by CaF8 polyhedra decorated on both sides by AlF6 octahedra, in turn connected to the {001} layer through edge-sharing. Successive {001} layers are bonded through Pb atoms. The new mineral honours Dr. Manuela Rossi (b. 1977) from the University of Naples for her contribution to the study of the Vesuvius volcano and its minerals.

Annivite-(Zn), Cu6(Cu4Zn2)Σ6Bi4S13, is a new IMA-approved mineral species from the Geister vein, Jáchymov ore district, Czech Republic. It occurs as anhedral grains, up to 50 μm in size, and growth zones, up to 100 μm in thickness, hosted by oscillatory zoned annivite-(Zn)/tennantite-(Zn) grains, and associated with Bi-rich tennantite-(Zn), tennantite-(Fe), tetrahedrite-(Zn), the not-yet approved ‘annivite-(Fe)’, bismuth, emplectite, wittichenite and supergene bismite, walpurgite and metazeunerite. In reflected light, annivite-(Zn) is isotropic, pale grey with a brownish shade and very rare pale brown internal reflections. Reflectance data for the four COM wavelengths in air are [λ (nm): R (%)]: 470: 32.3; 546: 32.0; 589: 32.0; 650: 31.6. Electron microprobe analysis gave (in wt.% – average of 5 spot analyses): Cu 36.29, Ag 0.14, Fe 0.08, Zn 7.11, Pb 0.19, As 6.07, Sb 4.50, Bi 21.08, S 23.68, total 99.14. On the basis of ΣMe =16 atoms per formula unit, the empirical formula of annivite-(Zn) is Cu10.13Ag0.02Zn1.93Fe0.03Pb0.02Bi1.79As1.43Sb0.66S13.10. Annivite-(Zn) is cubic, I$\bar 4$3m, with unit-cell parameters a = 10.3545(6) Å, V = 1110.16(19) Å3 and Z = 2. Its crystal structure was refined by single-crystal X-ray diffraction data to a final R1 = 0.0493 on the basis of 278 unique reflections with Fo > 4σ(Fo) and 23 refined parameters. Annivite-(Zn) is isotypic with other tetrahedrite-group minerals. Its crystal chemistry is discussed, and previous findings of Bi-rich tetrahedrite-group minerals are briefly reviewed, along with the description of a second finding of annivite-(Zn) from the abandoned Mauritius tin mine, Hřebečná, Krušné hory Mountains, Czech Republic.

Hakite-(Cd), hakite-(Fe) and hakite-(Zn) are new minerals belonging to the tetrahedrite group and forming, along with hakite-(Hg), the hakite series. They have been discovered in samples collected from the Bytíz deposit, in the uranium and base-metal Příbram ore district, Central Bohemia, Czech Republic. They occur as anhedral grains, up to 300 μm in size, in a calcite gangue, associated with clausthalite, cadmoselite, hakite-(Hg) [for hakite-(Cd)], berzelianite, bukovite, bytízite, crookesite, chaméanite, eskebornite, příbramite, the not yet approved giraudite-(Hg) and giraudite-(Cu), hakite-(Hg), umangite, chalcopyrite, tetrahedrite-(Zn) and a new Cu–As selenide [for hakite-(Fe) and -(Zn)]. The three new species are black, with a metallic lustre. Mohs hardness is ca. 3½–4; calculated density is 6.019 (Hak-Cd), 6.011 (Hak-Fe) and 6.081 g.cm–3 (Hak-Zn). In reflected light, they are isotropic, pale grey with bluish (Hak-Cd) or brownish (Hak-Fe and Hak-Zn) shades. Empirical formulae of hakite-(Cd), hakite-(Fe), and hakite-(Zn) are Cu9.71Ag0.24Cd1.51Hg0.43Zn0.03(Sb3.94As0.13)Σ4.07Se11.35S1.57, Cu10.11Ag0.18Fe0.81Zn0.50Hg0.26(Sb3.72As0.41)Σ4.13Se12.65S0.12, and Cu10.03Ag0.24Zn0.61Fe0.53Hg0.45(Sb3.55As0.60)Σ4.15Se12.82S0.08, respectively. These formulae correspond to the end-member formulae Cu6(Cu4Cd2)Sb4Se13 (Hak-Cd), Cu6(Cu4Fe2)Sb4Se13 (Hak-Fe), and Cu6(Cu4Zn2)Sb4Se13 (Hak-Zn). All these new members of the hakite series are cubic, I$\bar{4}$3m, Z = 2, with unit-cell parameters a = 10.8860(6) Å, V = 1290.0(2) Å3 (Hak-Cd); a = 10.7983(4) Å, V = 1259.12(14) Å3 (Hak-Fe); and a = 10.8116(14) Å, V = 1263.8(5) Å3 (Hak-Zn). These species are isotypic with the other members of the tetrahedrite group, and their crystal structures have been refined on the basis of single-crystal X-ray diffraction data down to R1 values of 0.0230 (Hak-Cd), 0.0254 (Hak-Fe), and 0.0302 (Hak-Zn). These structural data allow us to describe the S-to-Se partitioning in hakite-series minerals and to understand the mechanisms avoiding too short Me–Se distances in these selenides.

Markwelchite, ideally TlPbSbS3, is a new mineral from the hydrothermal deposit of Jas Roux, Hautes-Alpes, France. It occurs as a black anhedral crystal associated closely with protochabournéite. Microhardness measurements (VHN15) gave a mean value of 197 kg/mm2 corresponding to a Mohs hardness of ~3–4. In plane-polarised incident light, markwelchite is grey in colour. Under crossed polars, it is distinctly anisotropic with greyish white to bluish rotation tints, with bright red internal reflections. Reflectance percentages (Rmin and Rmax) are: 28.5, 31.5 (471.1 nm); 28.3, 30.7 (548.3 nm); 27.9, 30.3 (586.6 nm); and 27.6, 29.8 (652.3 nm). The mean of 5 electron microprobe spot analyses gave Tl 34.67(45), Pb 31.86(25), Sb 15.06(15), As 2.37(5), S 15.35(20), total 99.31 wt.%, corresponding, on the basis of a total of 6 atoms per formula unit and structural results, to Tl1.063Pb0.964(Sb0.775As0.198)Σ0.973S3.000. Single-crystal X-ray diffraction studies revealed that markwelchite is isotypic with richardsollyite, TlPbAsS3. It is monoclinic, space group P21/c, with the following unit-cell parameters: a = 8.9144(3), b = 8.4513(3), c = 8.6511(3) Å, β = 108.723(4)°, V = 617.27(4) Å3 and Z = 4. The five strongest observed powder-diffraction lines [d in Å (Irel)(hkl)] are: 3.88 (100)($\bar{2}$11); 3.78 (90)(210); 3.29 (90)(102); 2.73 (85)($\bar{1}$13); and 2.93 (75)(022). The crystal structure can be described as formed by (100) [Me2(SbS3)]– layers sandwiching the Me1+ cations. The Me1 site has a seven-fold coordination, whereas the Me2 site has an 6+2 coordination corresponding to a distorted, bicapped trigonal prismatic coordination, and the Sb site displays a trigonal pyramidal coordination with three S atoms and Sb at the apex.

The name markwelchite honours Dr Mark D. Welch of the Natural History Museum, London, UK.

The new mineral has been approved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (IMA2024–001). A discussion on the relationships between markwelchite and synthetic TlPbSbS3 is also provided.

Tetrahedrite-(Cu), Cu12Sb4S13, has been approved as a new mineral species (IMA2022–078) from the Bankov magnesite deposit near Košice, Slovak Republic where it occurs as anhedral grains, up to 0.4 mm across, associated with skinnerite, chalcostibite, famatinite, tetrahedrite-(Fe) and zoned aggregates of tennantite-(Cu) to tennantite-(Fe). Tetrahedrite-(Cu) is steel-grey, with a metallic lustre. Mohs hardness is ca. 3½–4 and calculated density is 5.029 g.cm–3. In reflected light, tetrahedrite-(Cu) is isotropic and grey with a bluish shade. Reflectance data for the four COM wavelengths in air are [λ (nm): R (%)]: 470: 31.1; 546: 30.1; 589: 29.9; and 650: 28.1. The empirical formula, based on electron-microprobe data (mean of 17 spot analyses), is Cu11.42Zn0.26Fe0.19(Sb4.06As0.08)Σ4.14S12.99. The ideal formula is Cu6(Cu4Cu2)Sb4S13, which requires (in wt.%) Cu 45.76, Sb 29.23 and S 25.01, total 100.00. Tetrahedrite-(Cu) is cubic, I$\bar{4}$3m, with unit-cell parameters a = 10.3296(15) Å, V = 1102.2(5) Å3 and Z = 2. Its crystal structure was refined by single-crystal X-ray diffraction data to a final R1 = 0.0347 on the basis of 261 unique reflections with Fo > 4σ(Fo) and 22 refined parameters. Tetrahedrite-(Cu) is isotypic with other tetrahedrite-group minerals. Previous findings of tetrahedrite-(Cu) are reported and some nomenclature issues, related to the Fe and Cu oxidation states, are discussed. At the Bankov deposit, tetrahedrite-(Cu) is related to hydrothermal, most probably Alpine, solutions strongly enriched in Cu, Sb and S.

Watanabeite from the Pefka epithermal deposit, northeastern Greece, was examined using single-crystal X-ray diffraction and electron microprobe analysis. The empirical formula of watanabeite is Cu3.93Fe0.10Ag0.01Pb0.23As1.55Sb0.19S4.99. This mineral is orthorhombic, space group Amm2, with unit-cell parameters a = 10.9601(5), b = 14.6498(8), c = 10.3001(5) Å, V = 1653.82(14) Å3 and Z = 8. The crystal structure was solved and refined to R1 = 0.0471 for 2108 unique reflections with Fo > 4σ(Fo) and 123 refined parameters. The crystal structure of watanabeite can be described as a three-dimensional framework of Cu-centred tetrahedra; cavities of the tetrahedral scaffolding host Cu6S and As2(Pb,Sb,As)2S7 clusters. On the basis of structural data, the formula of watanabeite could be written as [III]Cu3[IV]Cu5As3(Pb,Sb,As)S10 (Z = 4), considering the three independent three-fold Cu sites and the three independent tetrahedrally coordinated Cu sites as aggregated positions. The occurrence of Pb2+ in watanabeite is probably related to the substitution Cu+ + (As,Sb)3+ = 2Me2+, where Me = Pb, Fe, Zn and formally divalent Cu. The relationships with tetrahedrite-group minerals are discussed on the basis of the refined structural model, highlighting possible crystal chemical implications of such relationships.

Arsenoústalečite is a new mineral discovered in a sample collected from the abandoned Ústaleč deposit near Horažďovice, SW Bohemia, Czech Republic. It occurs as rare anhedral grains, up to 40 μm in size, in a calcite gangue, associated with stibioústalečite, hakite-(Hg), berzelianite and uraninite. Arsenoústalečite is dark grey, with a metallic lustre. Mohs hardness is ca. 3½–4; calculated density is 5.730 g/cm3. In reflected light, arsenoústalečite is pale grey with a yellowish shade; it is isotropic. Internal reflections were not observed. Reflectance values for the four COM wavelengths in air [R (%) λ (nm)] are: 33.3 (470); 33.1 (546); 33.0 (589); and 32.9 (650). The empirical formula of arsenoústalečite is (Cu5.81Ag0.17)Σ5.98(Cu5.95Fe0.02Zn0.02Hg0.01)Σ6.00(As1.40Sb0.87Te1.73)Σ4.00(Se10.30S2.32)Σ12.61. The ideal formula is Cu12(As2Te2)Se13, which requires (in wt.%) Cu 34.76, As 6.83, Te 11.63, Se 46.78, total 100.00. Arsenoústalečite is cubic, I$\bar{4}$3m, with unit-cell parameters a = 10.6580(19) Å, V = 1210.7(6) Å3 and Z = 2. The strongest reflections of the calculated powder X-ray diffraction pattern [d, Å (I, %) hkl] are: 3.077 (100) 222, 2.848 (10) 321, 1.946 (12) 521, 1.884(52) 440 and 1.608(21) 622. According to the single-crystal X-ray diffraction data (R1 = 0.0285 on the basis of 334 unique reflections with Fo > 4σFo and 24 refined parameters), arsenoústalečite is isotypic with other tetrahedrite-group minerals. The crystal structure of co-existing stibioústalečite, with an empirical formula of (Cu5.69Ag0.07)Σ5.76(Cu5.80Zn0.13Fe0.06Hg0.01)Σ6.00(Sb1.82As0.42Te1.76)Σ4.00(Se9.52S3.10)Σ12.62 and unit-cell parameters a = 10.6975(16) Å, V = 1224.2(5) Å3 and Z = 2, was refined to R1 = 0.0191 on the basis of 267 unique reflections with Fo > 4σFo and 24 refined parameters. Structural relationships and crystal-chemistry of both members of the ústalečite series are discussed. Arsenoústalečite is named after its type locality, the Ústaleč deposit and its chemical composition. The mineral and its name have been approved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (IMA2022-116).

Cotype material of stibiogoldfieldite from the Mohawk mine, Goldfield, Nevada, USA, has been examined in order to collect single-crystal X-ray diffraction data of Te-rich stibiogoldfieldite and to characterise the associated Ag–Bi–(S,Se) phase. Tellurium-rich stibiogoldfieldite, with empirical formula (Cu11.30Ag0.03)Σ11.33(Sb0.80As0.57Bi0.06Te2.57)Σ4.00(S12.83Se0.20)Σ13.03, is cubic, space group I$\bar{4}$3m, with unit-cell parameters a = 10.2947(3) Å and V = 1091.04(10) Å3. Its crystal structure has been refined to R1 = 0.0161 for 397 unique reflections with Fo > 4σ(Fo) and 25 refined parameters. The structure refinement confirmed the occurrence of a vacancy at the M(2) site, in agreement with the substitution M(2)Cu+ + X(3)(Sb/As)3+ = M(2)□ + X(3)Te4+. The Ag–Bi–(S,Se) phase was identified as the 6P homologue of the pavonite series, namely dantopaite. Its empirical formula is Cu1.36Ag4.39Pb0.12Bi12.62Sb0.06(S14.01Se7.91Te0.08), showing an exceptionally high Se content. Unit-cell parameters of Se-bearing dantopaite are a = 13.518(2), b = 4.0898(6), c = 18.984(3) Å, β = 106.816(6)°, V = 1004.7(3) Å3 and space group C2/m. The crystal structure was refined to R1 = 0.0504 for 1230 unique reflections with Fo > 4σ(Fo) and 82 refined parameters. The metal excess (~0.55 atoms per formula unit) of this pavonite homologue is mainly due to the accumulation of Ag and Cu in the thin slab of the crystal structure, whereas the high Se content is related to the partial replacement of S occurring preferentially in the thick PbS-like slab. Domains richer in Se and Pb in dantopaite, with empirical formula Cu0.89Ag4.50Pb0.49Bi12.53Sb0.07(S11.26Se10.74), were also identified, as grains up to 30 μm in size intimately intergrown with bohdanowiczite, indicating the possibility of a wide Se-to-S substitution in dantopaite.

A new member of the epidote supergroup, ferriandrosite-(Ce), ideally MnCeFe3+AlMn2+(Si2O7)(SiO4)O(OH), was found at the Július manganese ore occurrence near Betliar, Rožňava Co., Košice Region, Slovakia. It occurs as subhedral grains and polycrystalline aggregates, up to 0.3 mm in size, enclosed in pyroxmangite. Other associated minerals are spessartine, rhodochrosite, quartz, baryte and pyrosmalite-(Mn). Ferriandrosite-(Ce) is dark brown, with a light brown streak and vitreous lustre. The Mohs hardness is ~6½ to 7 and tenacity is brittle with no observable cleavage or fracture. The calculated density is 4.321 g⋅cm–3. Ferriandrosite-(Ce) is optically biaxial (+), with weak pleochroism, high surface relief and the mean calculated refractive index is 1.832. The empirical structural formula of ferriandrosite-(Ce), based on 13 anions per formula unit, is A1(Mn2+0.63Ca0.35Ce0.02)Σ1.00A2(Ce0.53La0.27Nd0.14Pr0.05REE*0.01)Σ1.00M1(Fe3+0.41Al0.12V3+0.01Mg0.40Ti0.05)Σ0.99M2Al1.00M3(Mn2+0.75Fe2+0.22Mg0.03)Σ1.00T1–3Si3.00O11O4(O0.67F0.33)(OH), where REE* are minor rare earth elements. Ferriandrosite-(Ce) is monoclinic, space group P21/m, a = 8.8483(4) Å, b = 5.7307(3) Å c = 10.0314(5) Å, β = 113.3659(15)°, V = 466.95(4) Å3 and Z = 2. The crystal structure of ferriandrosite-(Ce) was refined to a final R1 = 0.0210 for 1910 reflections with Fo > 4σ(Fo) and 127 refined parameters. Structural features of ferriandrosite-(Ce) are discussed and compared with other members of the androsite-series.

A new occurrence of austinite, CaZnAsO4(OH), conichalcite, CaCuAsO4(OH), and zincolivenite, CuZnAsO4(OH), is described from the Tripi mine, Peloritani Mountains, Sicily, Italy. These species have been observed in euhedral crystals in vugs of a calcite vein and were characterised using single-crystal X-ray diffraction, electron microprobe analysis and micro-Raman spectroscopy. Austinite and conichalcite have isotypic relations, both crystallising in space group P212121. Unit-cell parameters of austinite are a = 7.4931(5), b = 9.0256(6), c = 5.9155(4) Å, V = 400.06(5) Å3; its crystal structure was refined on the basis of 1210 unique reflections with Fo > 4σ(Fo) and 77 least-square parameters to R1 = 0.0236. Conichalcite has unit-cell parameters a = 7.419(10), b = 9.111(11), c = 5.867(7) Å and V = 396.6(1.4) Å3; the diffraction quality of its available grains was not good enough to allow a high-quality structural refinement. Chemical formulae of austinite and conichalcite are Ca1.04(1)Zn0.86(4)Cu0.09(4)As0.98(2)P0.02(1)O4(OH)0.98 and Ca0.98(1)Fe2+0.02(4)Cu0.69(10)Zn0.30(6)As0.97(2)P0.03(1)O4(OH)0.98, respectively. The new chemical data on the austinite–conichalcite isotypic pair, coupled with previous analyses, supports a possible miscibility gap between the compositions (Zn0.25Cu0.75) and (Zn0.50Cu0.50). Zincolivenite has unit-cell parameters a = 8.4594(9), b = 8.5324(8), c = 5.9893(6) Å, V = 432.30(12) Å3 and space group Pnnm; its crystal structure was refined to R1 = 0.0230 for 523 unique reflections with Fo > 4σ(Fo) and 47 least-square parameters. Its chemical composition is Cu0.73(5)Zn1.25(5)As1.01(1)O4(OH)1.01. The refinement of the crystal structure supports the ordering of Cu and Zn in two different crystallographic sites. Micro-Raman spectra of austinite, conichalcite and zincolivenite are discussed, with a focus on the O–H stretching region where local Zn and Cu arrangements affect the position of Raman bands in zincolivenite. These arsenates probably play an environmental role in the Peloritani area, where the occurrence of high contents of some potentially toxic elements in soils and stream sediments has been reported.

Vrančiceite is a new mineral species discovered in a sample collected from the old mine dumps of the abandoned Vrančice deposit near Příbram, central Bohemia, Czech Republic. Vrančiceite occurs as rare anhedral grains, up to 100 μm in size, in a calcite gangue, associated with cinnabar, djurleite, galena and hedyphane. Vrančiceite is black, with metallic lustre. Mohs hardness is ca. 2–3, calculated density is 6.652 g.cm–3. In reflected light, vrančiceite is light grey with a yellowish shade; bireflectance, pleochroism and anisotropy are all weak. Internal reflections were not observed. Reflectance values for the four Commission on Ore Mineralogy wavelengths of vrančiceite in air [Rmax, Rmin (%) (λ in nm)] are: 33.6, 31.2 (470); 33.9, 30.6 (546); 31.1, 30.0 (589); and 32.1, 29.1 (650). The empirical formula, based on electron-microprobe analyses, is Cu10.11(4)Ag0.01(1)Hg2.87(4)Sb0.01(1)Bi0.01(1)S7.99(8). The ideal formula is Cu10Hg3S8 (Z = 2), which requires (in wt.%) Cu 42.54, Hg 40.29 and S 17.17, total 100.00. Vrančiceite is triclinic, P$\bar{1}$, with unit-cell parameters a = 7.9681(2), b = 9.7452(3), c = 10.0710(3) Å, α = 77.759(1), β = 76.990(1), γ = 79.422(1)°, V = 737.01(4) Å3 and Z = 2. The strongest reflections of the calculated powder X-ray diffraction pattern [d, Å (I) hkl] are: 3.354 (76) $\bar{2}$01, 3.111 (68) 222, 2.833 (100) 213, 2.733 (93) 231, 2.705 (76) 2$\bar{2}$1 and 2.647 (71) $\bar{2}\bar{1}$2. According to the single-crystal X-ray diffraction data (R1 = 0.0262), the crystal structure of vrančiceite can be described as comprising Cu–S layers, connected through CuS3 polyhedra, giving rise to a three-dimensional framework with channels running along the a axis and hosting linearly coordinated Hg atoms. Structural relations with gortdrumite are discussed. Vrančiceite is named after its type locality, the Vrančice deposit near Příbram. The mineral and its name have been approved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (IMA2022–114).

Piccoliite, ideally NaCaMn3+2(AsO4)2O(OH), is a new mineral discovered in the Fe–Mn ore hosted in metaquartzites of the Montaldo di Mondovì mine, Corsaglia Valley, Cuneo Province, Piedmont, Italy. It occurs as small and rare black crystals and aggregates hosted by a matrix of quartz, associated with calcite and berzeliite/manganberzeliite. It has been also found in the Valletta mine near Canosio, Maira Valley, Cuneo Province, Piedmont, Italy, where it occurs embedded in quartz associated with grandaite, hematite, tilasite/adelite and rarely thorianite. The mineral is opaque (thin splinters may be very dark red), with brown streak and has a resinous to vitreous lustre. It is brittle with irregular fracture. No cleavage has been observed. The measured Mohs hardness is ~5–5.5. Piccoliite is non fluorescent. The calculated density is 4.08 g⋅cm–3. Chemical spot analyses by electron microprobe analysis using wavelength dispersive spectroscopy resulted in the empirical formula (based on 10 anions per formula unit) (Na0.64Ca0.35)Σ0.99(Ca0.75Na0.24)Σ0.99(Mn3+1.08Fe3+0.59Mg0.20Ca0.10)Σ1.97(As2.03V0.03Si0.01)Σ2.07O9(OH) and (Na0.53Ca0.47)Σ1.00(Ca0.76Na0.23Sr0.01)Σ1.00(Mn3+0.63Fe3+0.49Mg0.48Mn4+0.34Ca0.06)Σ2.00(As1.97P0.01Si0.01)Σ1.99O9(OH) for the Montaldo di Mondovì and Valletta samples, respectively. The mineral is orthorhombic, Pbcm, with single-crystal unit-cell parameters a = 8.8761(9), b = 7.5190(8), c = 11.689(1) Å and V = 780.1(1) Å3 (Montaldo di Mondovì sample) and a = 8.8889(2), b = 7.5269(1), c = 11.6795(2) Å, V = 781.43(2) Å3 (Valletta sample) with Z = 4. The seven strongest powder X-ray diffraction lines for the sample from Montaldo di Mondovì are [d Å (Irel; hkl)]: 4.85 (57; 102), 3.470 (59; 120, 113), 3.167 (100; 022), 2.742 (30; 310, 213), 2.683 (53; 311, 023), 2.580 (50; 222, 114) and 2.325 (19; 320, 214, 223). The crystal structure (R1 = 0.0250 for 1554 unique reflections for the Montaldo di Mondovì sample and 0.0260 for 3242 unique reflections for the Valletta sample) has MnO5(OH) octahedra forming edge-shared dimers; these dimers are connected through corner-sharing, forming two-up-two-down [[6]M2([4]TO4)4φ2] chains [M = Mn; T = As; φ = O(OH)] running along [001]. These chains are bonded in the a and b directions by sharing corners with AsO4 tetrahedra, giving rise to a framework of tetrahedra and octahedra hosting seven-coordinated Ca2+ and Na+ cations. The crystal structure of piccoliite is closely related to that of pilawite-(Y) as well as to carminite-group minerals that also show the same type of chains but with different linkage. The mineral is named after the mineral collectors Gian Paolo Piccoli and Gian Carlo Piccoli (father and son) (1926–1996 and b. 1953, respectively), the latter having discovered the type material at the Montaldo di Mondovì mine.

Following the identification of a new occurrence of melanostibite from the Apuan Alps, the crystal chemistry of this mineral has been re-examined using specimens from its type locality, Sjögruvan, Örebro County, Sweden, and from the new occurrence, the Scortico–Ravazzone Mn ore deposit, Apuan Alps, Tuscany, Italy. Both specimens were examined through electron microprobe analysis, micro-Raman spectroscopy and single-crystal X-ray diffraction data; Mössbauer spectroscopy was used for the Swedish specimen. Electron microprobe data indicate a close to ideal composition Mn2Fe3+Sb5+O6 for both samples, whereas Mössbauer spectroscopy confirmed the trivalent oxidation state of Fe. Single-crystal X-ray diffraction for the Swedish and Italian specimens points to the acentric nature of melanostibite, space group R3. Refined unit-cell parameters of melanostibite from Scortico–Ravazzone and Sjögruvan are a = 5.2351(3), c = 14.3645(8) Å, V = 340.93(4) Å3, and a = 5.2314(2), c = 14.3518(8) Å, V = 340.15(3) Å3, respectively. Melanostibite is an homeotypic derivative of pyrophanite.

Tennantite-(Cd), Cu10Cd2As4S13, was approved as a new mineral species from the Berenguela mining district, Pacajes Province, La Paz, Bolivia. It occurs as black metallic anhedral grains, up to 1 mm across, associated with baryte, montmorillonite and secondary Cd-sulfates (aldridgeite, niedermayrite and voudourisite). In reflected light, tennantite-(Cd) is isotropic and grey with brownish tints. Reflectance data for the four COM wavelengths in air are [λ (nm): R (%)]: 470: 30.0; 546: 30.1; 589: 28.2; and 650: 25.8. Electron microprobe analysis gave (in wt.% – average of 11 spot analyses): Cu 40.56(32), Ag 0.05(5), Fe 0.04(1), Zn 1.91(63), Cd 11.32(1.09), Hg 0.04(7), As 19.04(43), S 26.78(30), total 99.74(53). On the basis of ΣMe = 16 atoms per formula unit (apfu), the empirical formula of tennantite-(Cd) is Cu9.98Ag0.01Cd1.57Zn0.46Fe0.01As3.97S13.05. Tennantite-(Cd) is cubic, I$\bar{4}$3m, with unit-cell parameters a = 10.3088(2) Å, V = 1095.53(6) Å3 and Z = 2. Its crystal structure was refined by single-crystal X-ray diffraction data to a final R1 = 0.0152 on the basis of 359 unique reflections with Fo > 4σ(Fo) and 22 refined parameters. Tennantite-(Cd) is isotypic with other tetrahedrite-group minerals. Its crystal-chemistry is discussed and previous findings of Cd-rich tetrahedrite-group minerals are briefly reviewed.

Uvite, CaMg3(Al5Mg)(Si6O18)(BO3)3(OH)3(OH), is a new mineral of the tourmaline supergroup. It occurs in the Facciatoia quarry, San Piero in Campo, Elba Island, Italy (42°45′04.55″N, 10°12′50.89″E) at the centre of a narrow (2–3 cm wide) vein composed of aggregates of dark brown to black tourmaline, penetrating (magnesite + dolomite)-rich hydrothermally altered metaserpentinite. Crystals are euhedral and up to 1 cm in size, brown with a vitreous lustre, conchoidal fracture and grey streak. Uvite has a Mohs hardness of ~7½, a calculated density of 3.115 g/cm3 and is uniaxial (–). Uvite has trigonal symmetry, space group R3m, a = 15.9519(10) Å, c = 7.2222(5) Å, V = 1597.3(1) Å3 and Z = 3. The crystal structure was refined to R1 = 1.77% using 1666 unique reflections collected with MoKα X-rays. Crystal-chemical analysis resulted in the empirical crystal-chemical formula $^X ({\rm Ca}_{0.61}{\rm Na}_{{0.35}} \square_{{0.04}})_{\Sigma 1.00}{}^{Y} \left( {{\rm Mg}_{1.50}{\rm Fe}^{2 + }_{0.47} {\rm Al}_{0.71}{\rm Fe}^{3 + }_{0.14} {\rm Ti}_{0.18}} \right)_{\Sigma 3.00}$${}^{Z} \left( {{\rm Al}_{4.54}{\rm Fe}^{3 + }_{0.18} {\rm V}^{3 + }_{0.02} {\rm Mg}_{1.27}} \right)_{\Sigma 6.00}{}^{T}\left[ {{\left( {{\rm Si}_{5.90}{\rm Al}_{0.10}} \right)}_{\Sigma 6.00}{\rm O}_{18}} \right]{\rm } \left( {\rm BO_3} \right)_3^{} {^{\rm O(3)}}\left( {\rm OH} \right)_3{}^{{\rm O}\left( 1 \right)} [\left( {\rm OH} \right)_{0.55}{\rm F}_{0.05}{\rm O}_{0.40}]_{\Sigma 1.00}$

which recast in its ordered form for classification purposes is:

$$\eqalign{& ^{\rm X} ({\rm Ca}_{0.61}{\rm Na}_{0.35}\squ _{0.04})_{\Sigma 1.00}{}^{\rm Y} \left( {{\rm Mg}_{2.35}{\rm Fe}^{2 + }_{0.47} {\rm Ti}_{0.18}} \right)_{\Sigma 3.00} \cr & {}^{\rm Z} \left( {{\rm Al}_{5.25}{\rm Fe}^{3 + }_{0.32} {\rm V}^{3 + }_{0.02} {\rm Mg}_{0.42}} \right)_{\Sigma 6.00}{}^{\rm T} \left[ {{\left( {{\rm Si}_{5.90}{\rm Al}_{0.10}} \right)}_{\Sigma 6.00}{\rm O}_{18}} \right]{\rm }\left( {\rm BO_3} \right)_3{}^{\rm V} \left( {\rm OH} \right)_3{}^{\rm W} [\left( {\rm OH} \right)_{0.55}{\rm F}_{0.05}{\rm O}_{0.40}]_{\Sigma 1.00}}$$

Historical samples of branchite, described by the Tuscan naturalist Paolo Savi (1798–1871) at the end of the 1830s, were re-examined through single-crystal X-ray diffraction, showing their identity with hartite, C20H34, a hydrocarbon mineral described by Haidinger in 1841. The refined unit-cell parameters are a = 11.4116(7), b = 20.9688(12), c = 7.4100(4) Å, α = 93.947(2), β = 100.734(2), γ = 80.524(2)°, V = 1716.99(17) Å3 and Z = 4; space group P1. The crystal structure was solved and refined up to R1 = 0.0424 for 13512 reflections with Fo > 4σ(Fo) and 1265 refined parameters. As the name ‘branchite’ has priority over ‘hartite’, the reinstatement of the former name and the discreditation of the latter were approved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (IMA–CNMNC). Branchite is one of only eleven minerals formed by C and H listed in the official IMA List of Minerals. The type locality of branchite is the Botro di Lavajano, Monte Vaso, Chianni, Pisa, Tuscany, Italy. Neotype material is kept in the Natural History Museum of the Pisa University under catalogue number 14426.