Camerolaite Cu₄Al₂[HSbO₄,SO₄](OH)₁₀(CO₃).2H₂O, a new mineral from Cap Garonne mine, Var, France

Découverte d'une nouvelle espèce minérale dans l'ancienne mine de Cap Garonne, Var, France: la Camerolaite Cu4Al2[HSbO4,SO4](OH)10(CO3).2H2O

Calcio-andyrobertsite-2<I>O</I>, KCaCu<SUB>5</SUB>(AsO<SUB>4</SUB>)<SUB>4</SUB>[AsO<SUB>2</SUB>(OH)<SUB>2</SUB>]·2H<SUB>2</SUB>O: its description, crystal structure and relation with calcio-andyrobertsite-1<I>M</I>

Calcio-andyrobertsite-2O, ideally, CaCu5AsO4[AsO4(AsO2] • 2H2O, is a polytype of calcio-andyrobertsite-1 M, and occurs in a specimen of quartz gangue found at the Tsumeb mine, Namibia, together with cuprian adamite. It forms platy crystals with a maximum dimension of 7 × 3 × 0.5 mm. The intense blue crystals are elongated along [011] or [001], platy on {100}, and have a good cleavage on {100} and conchoidal fracture. They are not twinned. The mineral is orthorhombic, Pnma, a = 19.647(2), b, = 10.087(1), c = 9.963(1) Å, V = 1974.4(4) Å3, Z = 4, Dmeas= 3.9(1) and Dcalc= 3.80(1) g/cm3. The strongest lines in the X-ray powder diffraction pattern (dobs in Å, (hkl), Ivis) are: 9.80, (200), 50; 7.084, (011), 70; 6.665, (111), 60; 4.830, (102), 70; 4.487, (220), 90; 3.965, (302), 60; 3.116, (322)(610), 100; 2.760, (132), 90; 2.674, (431), 40; 1.758, (840)(11.01), 40. Mohs' hardness is 3 to 4. Lustre is vitreous, streak is pale blue; crystals are transparent and biaxial (−) with α = 1.715(5), β = 1.730(5), γ = 1.735(5) at 589 nm; 2Vobs= 55(5)°, 2Vcalc = 60(3)°. Pleochroism is moderate with γ = intense blue, β = blue, α = pale blue. The crystal structure was solved by direct methods (single crystal, MoKα radiation) and refined using all 1911 observed unique reflections to R(F) = 0.039, wR(F)=0.105.

Rollandite, Cu₃ (AsO₄)₂.4H₂O, a new mineral: its description and crystal structure

Rollandite, Cu3 (AsO4)2-4H2O, was found in the old copper mines of Roua (Alpes-Maritimes, France), associated with olivenite, conichalcite, clinotyrolite, cornubite, kolfanite, pharmacosiderite, gerhardtite, atacamite, gilmarite, wallkilldellite-Fe, cuprite, domeykite, algodonite and native copper. It forms aggregates (1mm diameter) consisting of perfect crystals (0.5 × 0.15 × 0.1 mm maximum dimension). The bottle-green crystals are elongated along a, slightly flattened on {010}, and have a good cleavage on {001}. They are not twinned. The mineral is orthorhombic, Pnma, a = 5.6906(4), b = 17.061(1), c = 9.732(1) Å, V = 944.9(1) Å3, Z = 4, Dmeas = 3.9(1) and Dcalc = 3.84 g/cm3. The strongest lines in the X-ray powder diffraction pattern (dobs in Å, (hkl), Ivis) are: 8.52, (020), 100; 3.721, (131), 60; 3.221, (141) (051), 90; 3.102, (132), 40; 2.817, (103)(033), 35; 2.795, (142), 35; 2.350, (143) (053), 25; 2.133, (080) (251), 25. Mohs' hardness is 4-4.5. Luster is vitreous transparent, streak is very light green; crystals are biaxial (-) with α = 1.745(5), β = 1.755(5), γ = 1.760(5) at 590 nm; 2Vobs = 71(2)°, 2Vcalc = 70.1(4)°. Non pleochroic. The crystal structure was solved by direct methods (MoKα radiation) and refined using 1407 observed unique reflections to R = 0.086, Rw = 0.046. The structure of rollandite is formed by (020) sheets of CulO6 octahedra and [100] chains of Cu2O5 square pyramids linked by AsO4 tetrahedra. The water molecule O6H2 is bonded by hydrogen bonds in the channels running along [100]

Yazganite, NaFe<SUP>3+</SUP><SUB>2</SUB>(Mg,Mn)(AsO<SUB>4</SUB>)<SUB>3</SUB>·H<SUB>2</SUB>O, a new mineral: its description and crystal structure

Yazganite, NaFe3+ 2(Mg, Mn)(AsO4)3• H2O, occurs in the andesitic rocks of the volcanic complex of Erciyes (prefecture of Kayseri, Turkey), associated with hematite, tridymite, cassiterite, magnetite, orpiment and realgar. It forms isolated prismatic crystals or aggregates formed by intergrown perfect crystals (10 x 3 x 2 mm maximum size). The crystals are brown to brown black color, showing a metallic luster. They are elongated along c and slightly flattened on {010}. Twinning was not observed. The mineral is monoclinic,C2/c, a = 12.181(1), b = 12.807(1), c = 6.6391(5) Å,β = 112.441(9)°, V = 957.2(2) Å3, Z = 4, D meas = 4.18(2) and D calc = 4.19 g/cm3 based on the crystal structure refinement. The strongest lines in the X-ray powder diffraction pattern (d obs in Å, (hkl), I obs) are: 6.40, (020), 20; 5.630, (200), 20; 3.575, (131), 30; 3.202, (040)(112), 40; 2.917, (312)(222), 35; 2.780, (240), 100; 2.611, (132), 40. The Mohs' hardness is about 5. The crystals are translucent and have adamantine luster, streak is bright brown to yellow gray; crystals are biaxial (−) with α = 1.870(2), β = 1.897(2), γ = 1.900(2) at 589 nm; 2Vobs = 35(2), 2Vcalc = 36.5(3). Pleochroism is moderate with α = orange brown, yellow; γ,β = grayish yellow, colorless. The crystal structure was solved by direct methods (MoKα radiation) and refined using 1528 observed unique reflections to Rw(F 2) = 0.073, R(F) = 0.029. The structure is a variant of the johillerite structure, which belongs to the alluaudite group. The mineral is the first example of a hydrated mineral from this group

Sur la présence de vuagnatite dans un gabbro ophiolitique du Guatémala

A new occurrence, as small grains associated with prehnite, chlorite and mesolite in a rodingitized hornblende gabbro of Guatemala, is reported for vuagnatite. The gabbro is part of the northern ultramafic zone of Guatemala. Physical and chemical data (microprobe analysis) are presented and are in excellent agreement with data for the Turkish vuagnatite

La Geminite Cu₂As₂O₇.3H₂O, un Nouveau Minéral de la Mine de Cap Garonne, Var, France

Description de la Geminite, une nouvelle espèce minérale découverte dans l'ancienne minde de Cap Garonne, près de Toulon, Var, France

Gysinite, Pb(Nd,La)(CO₃)₂(OH) · H₂O, a new lead, rare-earth carbonate from Shinkolobwe, shaba, Zaïre and its relationship to ancylite

Gysinite, ideally Pb(Nd,La)(C0₃)₂(OH) · H₂0, occurs at Shinkolobwe, Shaba, Zaïre, associated with schuilingite, malachite, cerussite, talc-chlorite, bornite, wulfenite, kasolite, native gold and garnet. The crystals, light pink to reddish pink in color, up to 1 mm in length, are euhedral with a pseudo-octahedral habit and with {111} and {110} as the most prominent forms. The streak is white to light pink. The name is to honor Professor Marcel Gysin. The crystal system is orthorhombic, space group Pmcn, with a = 5.04, b = 8.50, c = 7.25Å and Z = 2. a: b: c ratio is 0.5929: 1: 0.8529. The calculated density is 4.82 g/cm³. X-ray diffraction data are similar to those of ancylite. The mineral is biaxial negative with 2Vₓ = 70°, 2vcalc = 72.4°, α = 1.745, β = 1.805, γ = 1.840, dispersion r < v. Optical orientation: X = c, Y =a, Z= b

Présence de "Weilerite" dans l'Ancienne Mine de Cap Garonne, Var, France

Description de la Weilerite de l'ancienne mine de Cap Garonne, près de Toulon, Var, France