Weissite, Cu2–xTe (x ≈ 0.21), a very rare copper telluride, occurs in a sample from the Gambatesa mine, Val Graveglia, Liguria, Italy, where it occurs as purplish black anhedral grains up to 0.1 mm in length and shows a black streak. No cleavage is observed and the Vickers hardness (VHN100) is 142 kg/mm2. Weissite is dark bluish black, weakly pleochroic, and moderately anisotropic in bluish tints. Reflectance percentages in air for Rmin and Rmax are 37.0, 38.4 (471.1 nm), 33.2, 34.2 (548.3 nm), 31.2, 32.1 (586.6 nm), and 28.6, 31.0 (652.3 nm), respectively.Weissite is trigonal and belongs to the space group P3m1 with the following unit-cell parameters: a = 8.3124(7) Å, c = 21.546(1) Å, V = 1289.3(2) Å3, and Z = 24. Electron microprobe analyses gave the chemical formula (Cu1.62Ag0.04Au0.04Fe0.04Sb0.04)Σ=1.78(Te0.96S0.02Se0.02). The crystal structure has been solved and refined to R = 1.95%. It consists of Cu and Te polyhedra forming complex crystal-chemical environments as is typical of many intermetallic compounds. The exceedingly short bond distances observed among the metals are discussed in relation to other copper tellurides and pure metals.
The new mineral species canosioite, ideally Ba 2 Fe 3+ (AsO 4 ) 2 (OH), has been discovered in the dump of Valletta mine, Maira Valley, Cuneo Province, Piedmont, Italy. Its origin is probably related to the reaction between ore minerals and hydrothermal fluids. It occurs in reddish-brown granules, subhedral millimetre-size crystals, with a pale yellow streak and vitreous lustre. Canosioite is associated with aegirine, baryte, calcite, hematite, bronze Mn-bearing muscovite, unidentified Mn oxides and unidentified arsenates. Canosioite is biaxial (+) with a 2V meas = 84(2)°. It is weakly pleochroic with X = brownish yellow, Y = brown, Z = reddish brown, Z > Y > X. Canosioite is monoclinic, P2 1 /m, with a = 7.8642(4), b = 6.1083(3), c = 9.1670(5) Å, β = 112.874(6)°, V = 405.73(4) Å 3 and Z = 2. Calculated density is 4.943 g cm -3. The seven strongest diffraction lines of the observed powder X-ray diffraction pattern are [d in Å, (I) (hkl)]: 3.713 (18)(111) (AsO 4 ) 2 (OH). The crystal structure was solved by direct methods and found to be isostructural to that of arsenbrackebuschite. The structure model was refined (R 1 = 2.6%) on the basis of 1245 observed reflections. Canosioite is named after the small municipality of Canosio, where the type locality, the Valletta mine, is situated. The new mineral and name were approved by the International Mineralogical Association Commission on New Minerals and Mineral Names (IMA2015-030).
Two new monoclinic (P2 1 /m) epidote supergroup minerals manganiakasakaite-(La) and ferriakasakaite-(Ce) were found in the small Mn ore deposit of Monte Maniglia, Bellino, Varaita Valley, Cuneo Province, Piedmont, Italy. Manganiakasakaite-(La) occurs as subhedral grains embedded in pyroxmangite. Its empirical formula is A(1) (Ca 0.62 Mn 2+ 0.38 ) A(2) (La 0.52 Nd 0.08 Pr 0.07 Ce 0.07 Y 0.01 Ca 0.25 ) M(1) (Mn 3+ 0.52 Fe 3+ 0.28 Al 0.18 V 3+ 0.01 ) M(2) Al 1.00 M(3) (Mn 2+ 0.60 Mn 3+ 0.27 Mg 0.13 ) T(1−3) (Si 2.99 Al 0.01 ) O 12 (OH), corresponding to the end-member formula CaLaMn 3+ AlMn 2+ (Si 2 O 7 )(SiO 4 )O(OH). Unit-cell parameters are a = 8.9057(10), b = 5.7294(6), c = 10.1134(11) Å, β = 113.713(5) • , V = 472.46(9) Å 3 , Z = 2. The crystal structure of manganiakasakaite-(La) was refined to a final R 1 = 0.0262 for 2119 reflections with F o > 4σ(F o ) and 125 refined parameters. Ferriakasakaite-(Ce) occurs as small homogeneous domains within strongly inhomogeneous prismatic crystals, where other epidote supergroup minerals coexist [manganiandrosite-(Ce), "androsite-(Ce)", and epidote]. Associated minerals are calcite and hematite. Its empirical formula is A(1) (Ca 0.64 Mn 2+ 0.36 ) A(2) (Ce 0.37 La 0.17 Nd 0.06 Pr 0.03 Ca 0.35 0.02 ) M(1) (Fe 3+ 0.61 Al 0.39 ) M(2) Al 1.00 M(3) (Mn 2+ 0.64 Mn 3+ 0.33 Fe 3+ 0.02 Mg 0.01 ) T(1−3) Si 3.01 O 12 (OH), the end-member formula being CaCeFe 3+ AlMn 2+ (Si 2 O 7 )(SiO 4 )O(OH). Unit-cell parameters are a= 8.9033(3), b = 5.7066(2), c = 10.1363(3) Å, β = 114.222(2) • , V = 469.66(3) Å 3 , Z = 2. The crystal structure of ferriakasakaite-(Ce) was refined to a final R 1 = 0.0196 for 1960 unique reflections with F o > 4σ(F o ) and 124 refined parameters. Minerals 2019, 9, 353 2 of 15and 2 to the dollaseite group. Two additional minerals stand alone: zoisite, the unique example of epidote with orthorhombic symmetry, and åskagenite-(Nd), the unique example of epidote having a divalent anion dominant at the O(10) site. We herewith describe manganiakasakaite-(La) and ferriakasakaite-(Ce), two new minerals belonging to the allanite group. In this group, a trivalent cation, typically a REE, is dominant at the A(2) site, and a divalent cation is dominant at the M(3) site. According to the general guidelines for the nomenclature of epidotes [1], each distinct combination of dominant cations at the A(1) and M(3) sites deserves a proper root-name. In particular, the root-name "akasakaite" (after Masahide Akasaka, professor of mineralogy at the Shimane University) corresponds to the pair A(1) = Ca and M(3) = Mn 2+ [2]. Then, an adjectival prefix is appended to the root-name for the dominant cation at the M(1) (other than Al), and a Levinson suffix [3] is appended to the root-name for the dominant REE at the A(2) site. The names of the two new minerals are in keeping with the above guidelines, as they represent chemical variants of the mineral ferriakasakaite-(La), which was first described from Japan [2]. Both manganiakasakaite-(La) and ferriakasakaite-(Ce) were found in the Mn ore d...
was found in a pebble of the riverbed of the upper Maremola Creek, close to the village of Isallo, in the Magliolo municipality (Savona, Liguria, Italy). The root-name is after Monte Carmo di Loano, the highest peak in the area, namesake of the tectonic unit where the mineral was found and the first locality where phosphate mineralization has been found in the region. The mineral is associated with quartz and almandine and has microscopic inclusions of fluorapatite and possible graftonite. It occurs as yellow-orange and translucent crystals in an anhedral centimetric nodule embedded in quartz. Fluorcarmoite-(BaNa) is brittle, and no cleavage or parting was observed. It has a yellow-orange streak, a vitreous lustre, does not fluoresce under shortwave or longwave ultraviolet light and is weakly pleochroic (light yellow). Fluorcarmoite-(BaNa) is optically biaxial positive, with a = 1.6240(5), b = 1.6255(5), c = 1.6384(5) (589 nm), 2V meas = 35(2)°and 2V calc = 37.9°. Raman spectroscopy shows the presence of weak bands in the OH-stretching region. The average chemical composition is (wt%, wavelength-dispersive-mode electron microprobe):
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