ALBERT

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: A second occurrence of ferri-fluoro-leakeite has been identified in the Bratthagen nepheline syenite pegmatite (Vestfold County, Norway). With respect to the holotype found at the Verkhnee Espe deposit (Akjailyautas Mountains, Kazakhstan; Cámara et al. , 2010 ), it is closer to the ideal composition because of its larger Li and Mg contents and the absence of an oxo-component; however, it has a significant Zn content (0.29 a.p.f.u.). The ideal formula of ferri-fluoro-leakeite is A Na B Na C 2 (Mg 2 $${\mathrm{Fe}}_{2}^{3+}$$ Li) T Si 8 O 22 W F 2 and the empirical formula derived from electron-microprobe analysis and single-crystal structure refinement for the sample used here is A (Na 0.68 K 0.32 ) =1.00 B Na 2.00 C (Mg 1.69 $${\mathrm{Mn}}_{0.25}^{2+}$$ $${\mathrm{Fe}}_{0.24}^{2+}$$ Zn 0.29 Al 0.23 $${\mathrm{Fe}}_{1.50}^{3+}$$ Ti 0.02 Li 0.78 ) =5.00 T Si 8 O 22 W (F 1.59 (OH) 0.41 ) =2.00. Unit-cell data are a = 9.788(2), b = 17.826(3), c = 5.282(1) Å, β = 104.195(5)°, V = 893.5 (3) Å 3 , Z = 2. Crystal-chemical analysis shows that Li is ordered at the M (3) site and Zn is ordered mainly at the M (2) site, confirming previous findings for Li-bearing amphiboles. The new data also make quantification of the oxo component in Na amphiboles possible.

Description: Agakhanovite-(Y), ideally (YCa) 2 KBe 3 Si 12 O 30 , is a new milarite-group mineral from the Heftetjern pegmatite, Tørdal, southern Norway. Crystals are prismatic along [001], and show the forms {100} and {100}. Agakhanovite-(Y) is colorless with a white streak and a vitreous luster, and does not fluoresce under ultraviolet light. There is no cleavage or parting, and no twinning was observed. Mohs hardness is 6, and agakhanovite-(Y) is brittle with a conchoidal fracture. The calculated density is 2.672 g/cm 3 . Optical properties were measured with the Bloss spindle stage for the wavelength 590 nm using a gel filter. Agakhanovite-(Y) is uniaxial (–) with indices of refraction = 1.567, = 1.564, both ±0.002; the calculated birefringence is 0.003 and it is non-pleochroic. Agakhanovite-(Y) is hexagonal, space group P 6/ mcc , a = 10.3476(2), c = 13.7610(3) Å, V = 1276.02(9) Å 3 , Z = 2, c:a = 1.330. The seven strongest lines in the X-ray powder-diffraction pattern are as follows: d (Å), I , ( hkl ): 2.865, 100, (24); 3.287, 96, (31); 4.134, 84, (22); 6.877, 56, (002); 2.986, 43, (030); 4.479, 38, (020); 2.728, 36, (024). Chemical analysis by electron microprobe gave SiO 2 69.56, Al 2 O 3 0.35, Y 2 O 3 9.69, Yb 2 O 3 0.15, FeO 0.02 CaO 5.75, Na 2 O 0.07, K 2 O 4.52, BeO(calc) 7.06, H 2 O(calc) 1.74, sum 98.91 wt%. The H 2 O content was determined by crystal-structure analysis. On the basis of 30 anions, the empirical formula is (Y 0.89 Yb 0.01 Ca 1.06 ) 1.96 (H 2 O) 0.92 Na 0.02 K 1.00 (Be 2.93 Al 0.07 ) 3.00 Si 12.02 O 30 . The crystal structure of agakhanovite-(Y) was refined to an R 1 index of 1.9% based on 660 unique observed reflections collected on a three-circle rotating-anode (Mo K α X-radiation) diffractometer equipped with multilayer optics and an APEX-II detector. In the end-member structure of agakhanovite-(Y), the A site is occupied equally by Y and Ca, and the B site is vacant; agakhanovite-(Y) is the Y-analog of oftedalite: ScCa 2 KBe 3 Si 12 O 30 , and the Y-Ca-Be analog of klöchite, (Fe 2+ Fe 3+ ) 2 KZn 3 Si 12 O 30 .

Description: Aspedamite, ideally 12 (Fe 3+ ,Fe 2+ ) 3 Nb 4 [Th(Nb,Fe 3+ ) 12 O 42 ]{(H 2 O),(OH)} 12 , is a new heteropolyniobate mineral species from the Herrebøkasa quarry, Aspedammen, Østfold, southern Norway. It occurs as small euhedral crystals of dodecahedra and cubes to a maximum of 50 μm across, perched on a white mat of an Al–Nb–Fe–Ti–Ca–K-bearing silicate on a partly altered 12 x 12 x 6 mm crystal of monazite penetrated by plates of columbite-(Fe) and muscovite. Aspedamite is brownish orange with a very pale orange streak and an adamantine luster; it does not fluoresce under ultraviolet light. The Mohs hardness is 3–4, and it is brittle with a hackly fracture. The calculated density is 4.070 g/cm 3 , and the calculated index of refraction is 2.084. Aspedamite is cubic, space group Im , a 12.9078(6) Å, V 2150.6(3) Å 3 , Z = 2. The strongest seven lines in the X-ray powder-diffraction pattern [ d in Å( I ) hkl ] are: 9.107(100)011, 2.635(36)224, 2.889(33)024, 1.726(29)246, 3.233(28)004, 3.454(18)123, 4.567(15)022. A chemical analysis with an electron microprobe gave Nb 2 O 5 65.64, Ta 2 O 5 1.78, SiO 2 0.78, ThO 2 5.64, TiO 2 2.15, Fe 2 O 3 10.56, FeO 2.73, MnO 0.82, CaO 0.28, K 2 O 0.16, La 2 O 3 0.52, Ce 2 O 3 1.62, Nd 2 O 3 0.44, H 2 O (calc) 7.20, sum 100.32 wt.%; the H 2 O content was determined by crystal-structure analysis. The empirical formula of aspedamite on the basis of 54 anions with Fe 3+ /(Fe 3+ + Fe 2+ ) = 0.67 (estimated from crystal-chemical arguments) and O(4) = (H 2 O) 9 + (OH) 3 is K 0.09 Ca 0.13 Ce 0.26 La 0.08 Nd 0.07 Fe 2+ 1.00 Mn 0.30 Fe 3+ 3.48 Th 0.56 Ti 4+ 0.71 Si 0.34 Nb 12.98 Ta 0.21 O 42 (H 2 O) 9 (OH) 3 . The crystal structure of aspedamite was solved by direct methods and refined to an R 1 index of 1.6% based on 596 observed reflections collected on a three-circle rotating-anode (Mo K α X-radiation) diffractometer equipped with multilayer optics and an APEX-II detector. The structure is based on the heteropolyanion [ DA 12 O 42 ] ( D = Th, sum A = Nb 9 Fe 3+ 2 Ti), which consists of twelve face- and corner-sharing AO 6 octahedra that surround the [12]-coordinated D cation. There are eight heteropolyanions at the corners of the unit cell, with an additional heteropolyanion at the center, forming an I -centered arrangement. Each heteropolyhedral cluster is decorated by eight B octahedra, each of which bridges two adjacent clusters along the body diagonals of the cell. Further intercluster linkage is provided by the C octahedra, which link pairs of adjacent clusters in the a direction. Aspedamite is isostructural with menezesite.

Description: Ferrochiavennite is a new beryllium silicate zeolite with chemical composition close to Ca 1–2 FeSi 5 Be 2 O 13 (OH) 2 ·2H 2 O. It is described from two syenite pegmatite localities in Norway: Blåfjell, Langangen, Telemark, and the AS Granit larvikite quarry, Tvedalen, Vestfold. The mineral is monoclinic, P 2 1 / c , with a 8.759(5), b 4.864(2), c 31.258(6) Å, β 90.31(6)°, V 1331.7(6) Å 3 , and Z = 4. The crystal structure was refined to R 1 = 0.048 for 3651 observed reflections. The zeolite structure is isostructural with chiavennite, consisting of intersecting channels of nine-, six-, five-, and four-fold rings. The strongest eight reflections of the X-ray powder-diffraction pattern [ d (obs.) in Å ( I ) ( hkl )] are: 15.555 (100) (002), 4.104 (29) (12, 112), 3.938 (36) (13, 113), 3.909 (60) (008), 3.820 (30) (04, 204), 3.251 (66) (017, 210, 11), 3.186 (27) (12, 212), 2.884 (64) (15, 215). The mineral is biaxial (+) with refractive indices α 1.583(1), β 1.589(1), 1.602(1), measured at 590 nm. 2 V (meas.) = 62(4)° from extinction curves 2 V = 76(5)°; 2 V (calc.) = 69°. The optical orientation is X ~ a , Y ~ c , and Z ~ b . The Mohs hardness is ~ 3; D (meas.) = 2.67(2) and D (calc.) = 2.709 g/cm 3 .

Description: Hydroxylgugiaite, ideally (Ca 3 1 ) 4 (Si 3.5 Be 2.5 ) 6 O 11 (OH) 3 , is a new mineral species from two localities in the Larvik plutonic complex in Porsgrunn, Telemark, Norway, and one locality in Ilímaussaq, Greenland. Hydroxylgugiaite crystals occur as squat dipyramids {111} (30 x 50 μm) or as elongate tetragonal prisms. The crystals are translucent, white to pale grey in color, with a white streak and vitreous luster. It is brittle, with no apparent cleavage. Hydroxylgugiaite is uniaxial positive with = 1.622 ± 0.002 and = 1.632 ± 0.002. There is no pleochroism and birefringence is low. The average of eight analyses of a single grain of type material (oxide wt.%) gave Na 2 O 2.04, CaO 32.90, FeO 0.22, MnO 0.74, BeO 13.47 (LA-ICP-MS), Al 2 O 3 0.74, SiO 2 44.06, F 1.74, H 2 O (assuming 3 OH + F) 4.93, Total (–0.73 O = F) 100.10. Potassium, strontium, and magnesium were measured but not detected. The calculated density is 2.79 g cm –3 . The empirical formula on the basis of 14 anions including 3 OH – + F – is: (Ca 2.76 Na 0.31 Mn 0.05 Fe 0.01 ) 3.13 (Si 3.45 Be 2.53 Al 0.07 ) 6.05 O 11 [(OH) 2.57 F 0.43 ] 3 . The formula from crystal-structure analysis of the Saga specimen is: (Ca 3.02 0.98 ) 4 (Si 1.79 Be 0.21 ) 2 (Be 2.29 Si 1.71 ) 4 O 11 (OH) 3 . Combined structural and chemical data gives the following formula for the Nakkaalaaq specimen: (Ca 2.88 0.98 Na 0.12 Mn 0.02 ) 4 (Si 1.80 Be 0.17 Al 0.03 ) 2 (Be 2.32 Si 1.68 ) 4 O 11 [(OH) 2.70 F 0.30 ] 3 ; with simplified formula (Ca,) 4 (Si,Be) 2 (Be,Si) 4 O 11 (OH) 3 . The crystal structure of hydroxylgugiaite is tetragonal in acentric space group P 2 1 / m , with a 7.4151(2), b 7.4151, c 4.9652(1) Å, V 272.9(1) Å 3 , and Z = 1. It has been refined to an R index of 0.028 on the basis of 342 observed reflections and a correction for the {110} twin law. It is an H-bearing member of the melilite group. The structure has two distinct layers. The one crystallographically distinct Ca site with eight-fold coordination is a square antiprism polyhedron. The Ca polyhedra are in a layer with the H atoms. A second layer consists of corner-sharing Si/Be atoms in tetrahedral coordination with O. One H atom is bonded to an apical O atom that is not shared by two tetrahedra. This H atom is present only when there is a Ca -site vacancy. The other H atom is loosely bonded to the same O atom but at a different site. The IR spectrum supports this H-bonding scheme. Additional hydroxylgugiaite data is given for the other localities.

Description: Chiavennite (Mn endmember) and ferrochiavennite (Fe endmember) are beryllium silicate zeolites with chemical compositions close to Ca 1–2 (Mn,Fe)Si 5 Be 2 O 13 (OH) 2 ·2H 2 O. Five chiavennite crystals from four different localities, Chiavenna, Italy; Telemark, Norway; Utö, Sweden; and Ambatovita, Madagascar, were chosen for crystal-structure analysis. Initially all had been reported to be orthorhombic, but all are monoclinic, with a β angle near 90°, as is ferrochiavennite from Blåfjell, Norway. Twinning on {100} is common. Chiavennite and ferrochiavennite are isostructural. The zeolite structure consists of intersecting channels of nine-, six-, five-, and four-fold rings. All five structures have one Ca site in common while chiavennite from Utö and ferrochiavennite from Blåfjell have a second, partially filled, Ca site. Hydrogen atoms were located in all five structures. Hydrogen bonding is similar but not identical in all five structures. The H atoms associated with BeO 4 tetrahedra act as terminations to a polymerization sequence causing chiavennite and ferrochiavennite to be interrupted zeolite structures.