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Natromelansonite, Na3Zr[Si7AlO19]⋅4–5H2O, was found at the Poudrette (Demix) quarry, Mont Saint-Hilaire, Quebec, Canada in a highly altered pegmatite together with a clay mineral, steacyite, polylithionite and rhodochrosite. It occurs as an outer zone of tabular crystals to 0.1 × 0.3 × 1 mm in size flattened on (001). The inner zone is made of melansonite. The mineral is grey with white powder colour and vitreous lustre. The cleavage is parallel to {010}, perfect. The Mohs hardness is 3.5. The mineral has green fluorescence under short-wave ultraviolet light. The D calc is 2.31 g/cm3. The infrared spectrum is reported. The composition (wt.%, average of 8 analyses) is Na2O 10.08, K2O 1.72, CaO 0.24, BaO 0.32, MnO 0.10, Al2O3 6.86, Y2O3 0.35, Yb2O3 0.55, SiO2 56.23, ZrO2 14.78, H2O 9.52, total 100.75. The empirical formula calculated on the basis of O = 23 apfu and H = 8 apfu is Na(□Na0.38Ca0.02Mn0.01)2(Na0.70K0.28Ba0.02)Σ1.00(Zr0.91Y0.02Yb0.02)Σ0.95(Si7.08Al1.02)Σ8.10O19⋅4H2O. The mineral is monoclinic, P 21 /m , a = 6.5156(3) Å, b = 24.061(1) Å, c = 6.9759(6) Å, β = 90.453(5)° and V = 1093.61(9) Å3 and Z = 2. The strongest reflections of the powder X-ray diffraction pattern [ d ,Å(I)(hkl)] are: 12.02(100)(020), 6.97(89)(001), 6.51(39)(100), 3.416(37)(160), 3.062(42)($\bar{1}$ 61, 102, 161 and $\bar{1}$ 12), 3.018(38)(230 and 042), 2.864(40)(240 and 132). The crystal structure, solved and refined from single-crystal X-ray diffraction data (R 1 = 0.042), is based on a double sheet of tetrahedra (T) and a sheet of octahedra (O) that alternate along the [010] direction forming a TOT structure typical for members of the rhodesite mero-plesiotype series. [ABSTRACT FROM AUTHOR]

The new mckelveyite group mineral, alicewilsonite-(YLa), Na 2 Sr 2 YLa(CO 3) 6 ⋅ 3H 2 O, was found together with kamphaugite-(Y), paratooite-(Y), bastnäsite-(La), and decrespignyite-(Y) coating along fractures in dolomite at the Paratoo copper mine, South Australia, Australia. It occurs as pale pink to colourless pseudohexagonal tabular crystals up to 150 µ m in size. The streak is white; the lustre is vitreous. The mineral has no cleavage. Dcalc is 3.37 g cm -3. Alicewilsonite-(YLa) is optically biaxial (-), α = 1.556(2), β= 1.582(2), γ= 1.592(2), 2V (meas.) = 60(2)°, 2V (calc.) = 63° (589 nm). The IR spectrum is reported. The composition (wt %, average of seven analyses) is Na 2 O 7.43, CaO 2.00, SrO 18.43, BaO 1.64, Y 2 O 3 9.59, La 2 O 3 11.74, Pr 2 O 3 1.29, Nd 2 O 3 5.74, Sm 2 O 3 0.44, Eu 2 O 3 0.09, Gd 2 O 3 0.95, Dy 2 O 3 1.15, Ho 2 O 3 0.25, Er 2 O 3 0.89, Yb 2 O 3 0.29, CO 2 29.78, H 2 O 6.18, total 97.88. The empirical formula calculated on the basis of six cations with 3 H 2 O molecules is as follows: Na 2.10 Ca 0.31 Sr 1.56 Ba 0.10 Y 0.74 La 0.63 Pr 0.07 Nd 0.30 Sm 0.03 Eu 0.01 Gd 0.04 Dy 0.05 Ho 0.01 Er 0.04 Yb 0.01 (CO 3) 5.92 (H 2 O) 3. The mineral is triclinic, P 1, a= 8.9839(2), b= 8.9728(3), c= 6.7441(2) Å, α= 102.812(2)°, β= 116.424(2)°, γ= 60.128(2)°, and V= 422.17(2) Å 3 and Z= 1. The strongest reflections of the powder X-ray diffraction pattern [ d ,Å(I)(hkl)] are 6.03(43)(001), 4.355(100)(1 1‾ 0, 2‾1‾ 1, 120), 4.020(30)(1‾ 11, 210, 1‾2‾ 1), 3.188(29)(2‾1‾ 2, 1 1‾ 1, 121), 2.819(96)(002, 1‾ 12, 211, 1‾2‾ 2), 2.592(40)(3‾ 01, 030, 3‾3‾ 1), 2.228(33)(2‾ 21, 4‾2‾ 1, 2‾4‾ 1). 2.011(36)(2‾ 22, 003, 420, 2‾4‾ 2), 1.9671(32)(3‾ 03, 301, 0 3‾ 2, 032, 3‾3‾ 3, 331). The crystal structure was solved and refined from single-crystal X-ray diffraction data (R1= 0.058). [ABSTRACT FROM AUTHOR]

The new mineral bounahasite, Cu+Cu2+2(OH)3Cl2, was found in the oxidation zone of the Bou Nahas Mine, Morocco. It forms pseudo-hexagonal plates up to 3 × 30 × 40 μm in size combined in loose clusters with native copper and paratacamite. The mineral is green with vitreous lustre. The cleavage is parallel to {110}, perfect. D calc is 3.90 g/cm3. The infrared spectrum is reported. The composition (wt.%) is Cu2O 23.26, CuO 51.72, Cl 23.36, H2O 8.71, O = Cl2 –5.27, total 101.78. The empirical formula calculated on the basis of 3 Cu atoms per formula unit is: Cu+Cu2+2(OH)2.97Cl2.03. The mineral is monoclinic, P 21 /n, a = 8.5925(1), b = 6.4189(1), c = 10.4118(2) Å, β = 111.804(2)°, V = 533.17(2) Å3 and Z = 4. The strongest reflections of the powder X-ray diffraction pattern [ d ,Å(I)(hkl)] are: 7.71(70)($\bar{1}$ 01), 5.34(22)(011), 3.856(100)(012, $\bar{2}$ 02), 2.673(36)(022), 2.665 (30)(103) and 2.350 (71)($\bar{1}$ 23, 301, $\bar{2}$ 14). The crystal structure, refined from single-crystal X-ray diffraction data (R 1 = 0.028), is based on two alternating sheets coplanar to (110): one consists of alternating edge-sharing Cu2+(OH)6 octahedra and two Cu2+(OH)4Cl2 octahedra, whereas the other one is based on Cu+Cl4 tetrahedra forming edge-sharing Cu+2Cl6 dimers. [ABSTRACT FROM AUTHOR]

The new högbomite-group mineral magnesiohögbomite-6N12S, ideally Mg5Al11TiO23(OH), was found in calcite "vein-dikes" at the DeWitts Corners occurrence, lots 10 and 11, concession 1, Bathurst Township, Ontario, Canada. It forms tabular and short-prismatic crystals up to 5 mm in size. The major forms are pinacoid {0001} and hexagonal pyramid {11 ${\bar 2}$ 1}, sometimes modified by hexagonal prism {11 ${\bar 2}$ 0}. The associated minerals are magnesiohögbomite-2N3S, spinel, corundum, diopside, magnesio-hastingsite, pargasite, clinochlore and calcite. Magnesiohögbomite-6N12S is dark brown to black with brown streak and vitreous lustre. It has no cleavage and its fracture is uneven. The Mohs hardness is 6½. Dcalc is 3.87 g/cm3. The infrared spectrum is reported. The composition (wt.%) is MgO 13.09, ZnO 0.46, FeO 11.91, Fe2O3 6.84, Al2O3 62.70, TiO2 4.44, H2O 0.99, total 100.43. The empirical formula calculated on the basis of 17 cations, excluding H+, is (Mg2.95Fe2+1.51Al0.49Zn0.05)Σ5(Al10.71Fe3+0.78Ti0.51)Σ12O23(OH). The simplified formula is (Mg,Fe)5(Al,Fe,Ti)12O23(OH). The mineral is trigonal, R ${\bar 3}$ m, a = 5.7194(2), c = 83.069(5) Å, V = 2353.3(2) Å3 and Z = 6. The strongest reflections of the powder X-ray diffraction pattern [d,Å(I)(hkl)] are: 2.921(26)(0.1.23), 2.863(49)(110), 2.687(29)(0.1.26), 2.547(31)(0.1. $\overline{28}$) and 2.434(100)(1.1.18). The crystal structure was solved and refined from single-crystal X-ray diffraction data to R1 = 0.022. It is composed of alternating spinel (S) and nolanite (N) modules in the sequence 3 × (NSSNSS). The sequence of cubic 'c' and hexagonal 'h' closed-packed oxygen layers is 3 × (cccccchcccch). It is the first polysome in the högbomite supergroup with such a sequence. [ABSTRACT FROM AUTHOR]