ALBERT

Description: Waimirite-(Y) (IMA 2013-108), orthorhombic YF 3 , occurs associated with halloysite, in hydrothermal veins (up to 30 mm thick) cross-cutting the albite-enriched facies of the A-type Madeira granite (~1820 Ma), at the Pitinga mine, Presidente Figueiredo Co., Amazonas State, Brazil. Minerals in the granite are ‘K-feldspar’, albite, quartz, riebeckite, ‘biotite’, muscovite, cryolite, zircon, polylithionite, cassiterite, pyrochlore-group minerals, ‘columbite’, thorite, native lead, hematite, galena, fluorite, xenotime-(Y), gagarinite-(Y), fluocerite-(Ce), genthelvite–helvite, topaz, ‘illite’, kaolinite and ‘chlorite’. The mineral occurs as massive aggregates of platy crystals up to ~1 μm in size. Forms are not determined, but synthetic YF 3 displays pinacoids, prisms and bipyramids. Colour: pale pink. Streak: white. Lustre: non-metallic. Transparent to translucent. Density (calc.) = 5.586 g/cm 3 using the empirical formula. Waimirite-(Y) is biaxial, mean n = 1.54–1.56. The chemical composition is (average of 24 wavelength dispersive spectroscopy mode electron microprobe analyses, O calculated for charge balance): F 29.27, Ca 0.83, Y 37.25, La 0.19, Ce 0.30, Pr 0.15, Nd 0.65, Sm 0.74, Gd 1.86, Tb 0.78, Dy 8.06, Ho 1.85, Er 6.38, Tm 1.00, Yb 5.52, Lu 0.65, O (2.05), total (97.53) wt.%. The empirical formula (based on 1 cation) is (Y 0.69 Dy 0.08 Er 0.06 Yb 0.05 Ca 0.03 Gd 0.02 Ho 0.02 Nd 0.01 Sm 0.01 Tb 0.01 Tm 0.01 Lu 0.01 ) 1.00 [F 2.54 0.25 O 0.21 ] 3.00 . Orthorhombic, Pnma, a = 6.386(1), b = 6.877(1), c = 4.401(1) Å, V = 193.28(7) Å 3 , Z = 4 (powder data). Powder X-ray diffraction (XRD) data [ d in Å ( I ) ( hkl )]: 3.707 (26) (011), 3.623 (78) (101), 3.438 (99) (020), 3.205 (100) (111), 2.894 (59) (210), 1.937 (33) (131), 1.916 (24) (301), 1.862 (27) (230). The name is for the Waimiri-Atroari Indian people of Roraima and Amazonas. A second occurrence of waimirite-(Y) is described from the hydrothermally altered quartz-rich microgranite at Jabal Tawlah, Saudi Arabia. Electron microprobe analyses gave the empirical formula (Y 0.79 Dy 0.08 Er 0.05 Gd 0.03 Ho 0.02 Tb 0.01 Tm 0.01 Yb 0.01 ) 1.00 [F 2.85 O 0.08 0.07 ] 3.00 . The crystal structure was determined with a single crystal from Saudi Arabia. Unit-cell parameters refined from single-crystal XRD data are a = 6.38270(12), b = 6.86727(12), c = 4.39168(8) Å, V = 192.495(6) Å 3 , Z = 4. The refinement converged to R 1 = 0.0173 and w R 2 = 0.0388 for 193 independent reflections. Waimirite-(Y) is isomorphous with synthetic SmF 3 , HoF 3 and YbF 3 . The Y atom forms a 9-coordinated YF 9 tricapped trigonal prism in the crystal structure. The substitution of Y for Dy, as well as for other lanthanoids, causes no notable deviations in the crystallographic values, such as unit-cell parameters and interatomic distances, from those of pure YF 3 .

Description: Mn-bearing hellandite-(Y) occurs as pinkish yellow granular crystals (up to sub mm) in the Sc-rich granite pegmatite at Heftetjern, Tørdal, Telemark, Norway. Associated minerals are quartz, albite, Sc- and Ce-bearing epidote, hingganite-(Y), and an undetermined Ca-bearing hingganite-related mineral. Electron microprobe analyses give an empirical formula as Ca 1.34 Mn 1.07 Y 2.75 Ce 0.02 Nd 0.02 Sm 0.01 Gd 0.01 Dy 0.05 Er 0.05 Yb 0.15 Al 0.94 Fe 0.08 Si 3.99 B 4.33 O 22.00 (OH) 2.00 on the basis of Al+Fe+Si = 5 and 24 anions per formula unit. The lattice parameters were refined from diffraction data obtained using a Gandolfi camera with an imaging plate and Ni filtered Cu K α; a 18.693(17), b 4.651(3), c 10.178(7) Å, β = 111.37(6)°, V 824.1(10) Å 3 . The crystal structure was refined from single-crystal XRD data obtained with a CCD-diffractometer and graphite-monochromated Mo K α. The refinement with anisotropic atomic displacement parameters converged to R 1 = 0.0269 for 1567 reflections [ I 〉 2( I )] and 0.0318 for all 1768 reflections, resulting in the structural formula M 3 (Ca 0.56 Mn 0.44 ) 2 M 4 (Y 0.43 Ca 0.23 Ln 0.14 0.20 ) 2 M 2 (Y 0.94 Ln 0.06 ) 2 M 1 (Al 0.92 Fe 0.08 )Si 4 B 4 O 21.21 (OH) 2.79 . In this hellandite-(Y), Mn 2+ replaces Ca 2+ at the M 3 site and there is a significant vacancy at the M 4 site. The T site is vacant, and, instead, the O5 position is occupied by (OH) – .

Description: The growth history of quartz twinned according to the Japan law and the development of fine textures near Japan twin boundaries were analysed using optical microscopy, cathodoluminescence, and computational simulations. Cathodoluminescence images of the samples show two distinct growth stages. In the early growth stage, growth sectors of rhombohedral faces bordered by the {11 $$\overline{2}$$ 2} composition plane serve as preferential growth sites that grow approximately 1.5–1.8 times faster than the other symmetrically equivalent faces. Thus, the samples initially exhibit a "fan-shape". The composition plane is quite straight and parallel to {11 $$\overline{2}$$ 2} in the growth sectors of rhombohedral faces but undulates in the growth sectors of prism faces. In the later growth stage, the twinned crystals grow rather isotropically and change into "V-shape". Prism faces start to develop at the composition plane, which is no longer parallel to {11 $$\overline{2}$$ 2}. Observations of etched figures show that fine Brazil twin lamellae are concentrated almost exclusively near the Japan twin boundary. In the early growth stage, polysynthetic Brazil twin lamellae are formed in an hourglass-shaped sector, and the lamellae develop progressively as the Japan twin grows. However, there are considerably fewer lamellae in the later growth stage. Structures at the intersection of Japan and Brazil twin boundaries were modelled using molecular dynamics simulations. The intersections of Brazil and Japan twin boundaries were found to be structurally coherent when they have certain composition planes. The results imply that Japan twin boundaries only have structural diversity, allowing either right-handed or left-handed quartz to grow coherently on the substrate crystals, when the composition plane of Japan twin is parallel to {11 $$\overline{2}$$ 2} and rhombohedral faces are bordered by the {11 $$\overline{2}$$ 2} composition plane. This structural diversity of the {11 $$\overline{2}$$ 2} Japan twin boundaries causes development of fine Brazil twin lamellae and triggers faster growth rate of rhombohedral faces bordered by the straight {11 $$\overline{2}$$ 2} composition plane.

Description: Imayoshiite, Ca 3 Al(CO 3 )[B(OH) 4 ](OH) 6 ·12H 2 O, occurs in cavities in the altered gabbro xenolith in the sepentinized dunite exposed at Suisho-dani, Ise City, Mie Prefecture, Japan. Imayoshiite is colourless and transparent with a vitreous lustre and its aggregates are white with a silky lustre. Imayoshiite has a white streak. Its Mohs hardness is 2–3. It is brittle, the cleavage is distinct on {100} and the fracture is uneven. The mineral is uniaxial (–) with the indices of refraction = 1.497(2) and = 1.470(2) in white light. Imayoshiite is hexagonal, P 6 3 , a = 11.0264(11), c = 10.6052(16) Å by powder diffraction and a = 11.04592(2), c = 10.61502(19) Å by single-crystal diffraction. The structural refinement converged to R 1 = 2.35%. Imayoshiite is the first member of the ettringite group with both CO 3 and B(OH) 4 anions.

Description: Shimazakiite occurs as greyish white aggregates up to 3 mm in diameter. Two polytypes, shimazakiite-4 M and shimazakiite-4 O , have been identified, the former in nanometre-sized twin lamellae and the latter in micrometre-sized lamellae. Shimazakiite was discovered in an irregular vein in crystalline limestone near gehlenite-spurrite skarns at Fuka mine, Okayama Prefecture, Japan. Associated minerals include takedaite, sibirskite, olshanskyite, parasibirskite, nifontovite, calcite and an uncharacterized hydrous calcium borate. The mineral is biaxial (–), with the following refractive indices (at 589 nm): α = 1.586(2), β = 1.650(2), = 1.667(2) and 2V calc = 53° [shimazakiite-4 M ]; and α = 1.584(2), β = 1.648(2), = 1.670(2) and 2V calc = 54.88° [shimazakiite-4 O ]. Quantitative electron-microprobe analyses (means of 28 and 25 determinations) gave the empirical formulae Ca 2 B 1.92 O 4.76 (OH) 0.24 and Ca 2 B 1.92 O 4.76 (OH) 0.24 for shimazakiite-4 M and shimazakiite-4 O , respectively. The crystal structure refinements: P 2 1 / c , a = 3.5485(12), b = 6.352(2), c = 19.254(6) Å, β = 92.393(13)°, V = 433.6(3) Å 3 [for shimazakiite-4 M ]; and P 2 1 2 1 2 1 , a = 3.55645(8), b = 6.35194(15), c = 19.2534(5) Å, V = 434.941(18) Å 3 [for shimazakiite-4 O ], converged into R 1 indices of 0.1273 and 0.0142, respectively. The crystal structure of shimazakiite consists of a layer containing B 2 O 5 units (two near-coplanar triangular corner-sharing BO 3 groups) and 6- and 7-coordinate Ca atoms. Different sequences in the c direction of four layers are observed in the polytypes. The five strongest lines in the powder-diffraction pattern [listed as d in Å( I )( hkl )] are: 3.02(84)(022); 2.92(100)(104I) 2.81(56)(104); 2.76(32)(113); 1.880(32)(118I,126I,126,118) [for shimazakiite-4 M ]; and 3.84(33)(014); 3.02(42)(022); 2.86(100)(104); 2.79(29)(113); 1.903(44)(126,118) [for shimazakiite-4 O ].

Description: Minohlite, a new copper-zinc sulfate mineral related to schulenbergite, was found in the oxidized zone of the Hirao mine at Minoh (Minoo) City, Osaka Prefecture, Japan. The mineral occurs in cracks in altered shale as rosette aggregates up to 100 μm in diameter, composed of hexagonal platy crystals up to 50 μm in diameter and 10 μm in thickness. The associated minerals are chamosite, muscovite, smithsonite, serpierite, ramsbeckite, ‘limonite’ and chalcopyrite. Minohlite has hexagonal (or trigonal) symmetry with unit-cell parameters of a = 8.2535(11), c = 8.1352(17) Å, V = 479.93(16) Å 3 and Z = 1, and possible space groups P 6, P 6I, P 6/ m , P 622, P 6 mm , P 6I 2 m and P 6/ mmm (or P 3, P 3I, P 321, P 3 m 1, P 3I m 1, P 312, P 31 m and P 3I1 m ). The six strongest reflections in the powder X-ray diffraction pattern [ d in Å ( I ) hkl ] are 8.138 (20) 001; 4.128 (24) 110; 2.702 (100) 120; 2.564 (76) 121; 1.560 (43) 140; and 1.532 (24) 141. Electron microprobe analyses gave the following values (wt.%): CuO 37.18, ZnO 21.08, FeO 0.49, SO 3 16.78, SiO 2 0.44, and H 2 O 24.03 (by difference). The empirical formula, calculated on the basis of Cu + Zn + Fe + S + Si = 9 atoms per formula unit, is (Cu 4.43 Zn 2.45 Fe 0.06 ) 6.94 [(SO 4 ) 1.99 (SiO 4 ) 0.07 ] 2.06 (OH) 9.64 ·7.81H 2 O, which leads a simplified formula of (Cu,Zn) 7 (SO 4 ) 2 (OH) 10 ·8H 2 O where Cu 〉 Zn. The mineral is bluish-green and transparent with a pearly to vitreous lustre. The streak is pale green. Cleavage is perfect on {001}. The Mohs hardness number is less than 2. The calculated density is 3.28 g cm –3 . The mineral is named after Minoh City, where it was discovered.

Description: Two new members of the atacamite family were discovered recently in the Sadamisaki Peninsula, Ehime Prefecture, Japan. Iyoite, MnCuCl(OH) 3 , is an Mn-Cu ordered analogue of botallackite, while misakiite, Cu 3 Mn(OH) 6 Cl 2 , is an Mn-rich analogue of kapellasite. Both minerals occur in manganese ore crevices in close association with one another. Iyoite forms radial and dendritic aggregates consisting of pale green, bladed crystals. Misakiite commonly exists in emerald green, tabular, hexagonal crystals. The densities of iyoite and misakiite were calculated to be 3.22 and 3.42 g cm –3 based on their empirical formulae and powder X-ray diffraction data. Under the same axial setting of botallackite, iyoite is monoclinic, space group P 2 1 / m , a = 5.717(2), b = 6.586(2), c = 5.623(3) Å, β = 88.45(3)° and V = 211.63(15) Å 3 . Misakiite is trigonal, space group P m 1, with a = 6.4156(4), c = 5.7026(5) Å and V = 203.27(3) Å 3 . The structures of both minerals are classified as layer type and the two are closely related. These new minerals were formed by the reaction between seawater and naturally-occurring manganese ores including native copper. These minerals are challenging to produce synthetically. Misakiite was synthesized successfully using a hydrothermal method, while iyoite could not be made.