AbstractThe new mineral nafeasite (IMA2021-103), NaFe3+(AsO3OH)2⋅H2O, was found at the Torrecillas mine, Iquique Province, Chile, where it is a secondary alteration phase associated with anhydrite, gypsum, halite, lavendulan, magnesiokoritnigite and natrojarosite. Nafeasite occurs in tightly intergrown aggregates of equant crystals. Crystals are light to medium pink and transparent, with vitreous lustre and white streak. The Mohs hardness is ~2½. The density is 3.23(2) g⋅cm–3. Optically, nafeasite is biaxial (+), with α = 1.679(3), β = 1.682(3), γ = 1.730(5) (white light); 2V = 27(2)°; and slight r < v dispersion. The empirical formulae of the holotype and cotype (based on 9 O atoms per formula unit) are Na0.98K0.02Fe0.92Al0.07As2.00O9H4.01 and Na0.97Fe0.68Al0.33As2.00O9H4.01, respectively. Nafeasite is monoclinic, space group C2, with cell parameters: a = 18.6876(16), b = 8.6769(7), c = 14.8100(10) Å, β = 105.238 (5)°, V = 2317.0(3) Å3 and Z = 12. The structure, refined to R1 = 5.03% for 5979 Io > 2σI reflections, is based on a loose 3D framework of alternating AsO3OH tetrahedra and Fe3+O6 octahedra.

The mineral vondechenite (IMA 2016-065), CaCu4Cl2(OH)(8) center dot 4H(2)O, is a blue hydrous calcium copper chloride hydroxide with a new structure type. The translucent mineral has a vitreous lustre, exhibits a pale blue streak and shows a distinct pleochroism. Its crystals form tiny aggregates of platy crystals not exceeding 1 mm in diameter. Isolated imperfect tabular crystals with {010} as the dominant form are smaller. They have a diameter of not more than 0.5 mm and a thickness of less than 25 mu m. Vondechenite is not fluorescent and shows a good cleavage on (010). The name vondechenite is for Ernst Heinrich von Dechen a scientific pioneer for the geology of the western part of Germany. Vondechenite is orthorhombic with space group symmetry Cmcm. Cu atoms are arranged in layers with a pseudo-square topology. Ca atoms are disordered with 48 % vacancies, but streaks of diffuse scattering parallel b* might indicate ordered layers of Ca atoms, with no long range order in b* direction. Unit cell parameters determined by X-ray single crystal diffraction are a = 6.653(1) angstrom, b = 15.034(3) angstrom, c = 6.611(1) angstrom, V = 661.3 (2) angstrom(3) and Z = 2. The calculated density is 2.85 g/cm(3). The strongest lines observed in the simulated X-ray powder diffraction pattern are [d in angstrom/I-rel in %] 7.60/100; 2.48/58; 2.52/49; 3.07/39; 1.73/39. Electron microprobe analyses gave (wt.%) CaO 10.44, CuO 58.25, Fe 0.33, Cl 13.31, O Cl-3.01, H2 Ocalc. 25.14, sum 104.44 wt.% leading to an empirical formula of Ca-1.01(Cu3.97Fe0.02)Cl-2.03 (OH)(7.97) center dot 3.58H(2)O based on 5 cations pfu. The simplified formula is CaCu4Cl2(OH)(8) center dot 4H(2)O which requires CaO 9.78, CuO 55.50, Cl 12.37 (O Cl-2.79), H2O 25.14, total 100.00 wt.%. The new mineral was collected in 1993 in the northern part of the Caspar quarry, Bellerberg volcano, East-Eifel volcanic area, Rhineland-Palatinate, Germany. Vondechenite was found in a xenolith of the Bellerberg basalt in a matrix of white ettringite and jennite.

Ianbruceite, ideally [Zn-2(OH)(H2O)(AsO4)](H2O)(2), is a new supergene mineral from the Tsumeb mine, Otjikoto (Oshikoto) region, Namibia. It occurs as thin platy crystals up to 80 mu m long and a few mu m thick, which form flattened aggregates up to 0.10 mm across, and ellipsoidal aggregates up to 0.5 mm across. It is associated with coarse white leiteite, dark blue kottigite, minor legrandite and adamite. Ianbruceite is sky blue to very pale blue with a white streak and a vitreous lustre; it does not fluoresce under ultraviolet light. It has perfect cleavage parallel to (100), is flexible, and deforms plastically. The Mohs hardness is 1 and the calculated density is 3.197 g cm(-3). The refractive indices are alpha = 1.601, beta = 1.660, gamma = 1.662, all +/- 0.002; 2V(obs) = 18(2)degrees, 2V(calc) = 20 degrees, and the dispersion is r < v, weak. Ianbruceite is monoclinic, space group P2(I)/c, a = 11.793(2), b = 9.1138(14), c = 6.826500) angstrom, beta = 103.859(9)degrees, V = 712.3(3) angstrom(3), Z = 4, a:b:c = 1.2940:1:0.7490. The seven strongest lines in the X-ray powder diffraction pattern [d (angstrom), I, (hkI)] are as follows: 11.29, 100, (100); 2.922, 17, (130); 3.143, 15, (<(2)over bar>02); 3.744, 11, (300); 2.655, 9, (230); 1.598, 8, ((1) over bar 52); 2.252, 7, (222). Chemical analysis by electron microprobe gave As2O5 36.27, As2O3 1.26, Al2O3 0.37, ZnO 49.72, MnO 0.32, FeO 0.71, K2O 0.25, H2Ocalc 19.89, sum 108.79 wt.%; the very high oxide sum is due to the fact that the calculated H2O content is determined from crystal-structure analysis, but H2O is lost under vacuum in the electron microprobe.The crystal structure of ianbruceite was solved by direct methods and refined to an R-1 index of 8.6%. The As is tetrahedrally coordinated by four O anions with a mean As-O distance of 1.687 angstrom. Zigzag [(ZnZr)-Zn-[5]-Zr-[6]phi(7)] chains extend in the c direction and are linked in the b direction by sharing corners with (AsO4) tetrahedra to form slabs with a composition [Zn-2(OH)(H2O)(AsO4)]. The space between these slabs is filled with disordered (H2O) groups and minor lone-pair stereoactive As3+. The ideal formula derived from chemical analysis and crystal-structure solution and refinement is [Zn-2(OH)(H2O)(AsO4)](H2O)(2).

The new mineral hermannroseite (IMA-CNMNC No. 2010-006) has the chemical formula CaCu(PO4,AsO4)(OH). It is the phosphate analogue of conichalcite, CaCu(AsO4)(OH) and belongs to the adelite group where it represents the first phosphate end-member of this group. Hermannroseite is orthorhombic with space group P2(1)2(1)2(1). X-ray powder diffraction studies gave a: 7.328(7), b: 9.123(7), c: 5.769(6) angstrom, V = 385.7(6) angstrom(3) , Z = 4. The strongest reflections in the X-ray powder diffraction data are as follows d(obs). (angstrom) (I, hkl): 2.808 (100, 130), 2.571 (73, 112), 3.092 (63, 201), 5.710 (56, 110) and 4.057 (37, 111). Hermannroseite was found in the Tsumeb mine, Tsumeb, Namibia. With a mean grain size of 0.7 mu m hermannroseite occurs within botryoidal agge-gates and crusts of micro crystalline conichalcite in association with hydroxylapatite, whitlockite, pseudomalachite and amorphous manganese oxides/hydroxides.Hermannroseite is translucent with a vitreous green colour. The calculated density is 4.08 g/cm(3), the calculated mean refractive index is 1.77. Chemical analyses gave (wt.%): CaO 22.80, CuO 34.52, ZnO 0.58, P2O5 15.16, As2O5 21.88, V2O5 1.02, H2O(by difference) 4.04, sum 100.00 wt.%. The resulting empirical formula based on 5 anions is Ca-0.96(Cu1.03Zn0.02)(P(0.51)AS(0.45)V(0.03)) O-3.94(OH)(1.06).

The new mineral krieselite (IMA-CNMNC No. 2000-043a) has the ideal chemical formula Al2GeO4(F,OH)(2) and is the Ge analogue of topaz. Krieselite was found in the Tsumeb mine, Tsumeb, Namibia. It occurs as beige to white, hemispherical aggregates and crusts of fibrous crystals and is closely associated with quartz, wulfenite, anglesite, and graphite. The fibers are up to 50 mu m long and up to 5 mu m thick. Krieselite aggregates are translucent with a greasy luster. The streak is white. The name of the new mineral is in honor of F. W. KRIESEL, who was the chief chemist and head of the Tsumeb mine laboratory around 1920. Chemical analyses by electron microprobe, neutron activation, and proton-induced X-ray fluorescence yielded the chemical formula (Al-1.860,Ga-0.102,As-0.036(+3),Zn-0.020,Mg-0.016,Fe-+0.012(3),Na-0.009,Sb-+0.005(3),Ti-0.003,Cu-0.001)(Sigma 2.064)(Ge-0.844,Al-0.143,Si-0.013)(Sigma 1.000)O-4(F1.103OH0.897)(Sigma 2.000). Krieselite crystallizes in the space group Pbnm ( 62). Unit cell parameters refined from X-ray powder diffraction data are a = 4.809(2) angstrom, b = 9.111(3) angstrom, c = 8.536(3) angstrom, V = 374.0(3) angstrom(3), Z = 4. Using Cu K alpha radiation the five strongest reflections in the X-ray powder diffraction data are as follows: d(obs). (angstrom) (I, hkl): 3.016 (100, 112), 3.811 (78, 111), 3.315 (48, 012), 2.247 (38, 211) and 2.417 (27, 023/200). The calculated density and calculated mean refractive index are 4.07 g/cm(3) and 1.74, respectively.

Bendadaite, ideally Fe(2+)Fe(2)(3+)(AsO(4))(2)(OH)(2 center dot).4H(2)O, is a new member of the arthurite group It was found as a weathering product of arsenopyrite on a single hand specimen from the phosphate pegmatite Bendada. central Portugal (type locality) Co-type locality is the granite pegmatite of La via do Almerindo (Almerindo mine), Linopolis, Divmo das Laranjeiras county, Minas Gerais, Brazil Further localities are the Vein Negra mine, Copiapo province, Chile, mid-East, Bou Azzer district, Morocco, and Para Inferida yard, Fenugu Sibirt mine, Gonnosfanadiga, Medio Campidano Province, Sardinia. Italy Type bendadaite occurs as blackish green to dark brownish tufts (<0 1 mm long) and flattened radiating aggregates. in intimate association with an intermediate member of the scorodite-mansfieldite series It is monoclinic. space group P2(l/c). with a = 10 239(3) angstrom. b = 9 713(2) angstrom, c = 5 552(2) angstrom. beta = 94 11(2)degrees. = 550 7(2) angstrom(3). Z = 2 Electron-microprobe analysis yielded (wt %). CaO 0 04, MnO 0 03. CuO 006, ZnO 004. Fe(2)O(3) (total) 43 92, Al(2)O(3) 115. SnO(2) 0 10, As(2)O(5) 43 27. P(2)O(5) 1 86, SO(3) 0.03 The empirical formula is (Fe(0 52)(2+)Fe(0 32)(3+)rectangle(0 16))(Sigma 1 00)(Fe(1 89)(3+)Al(0 11))(Sigma 2 00)(As(1 87)P(0 13))(Sigma 2 00)O(8)(OH)(2 00) 4H(2)O based. CM 2(As,P) and assuming ideal 80, 2(OH), 4H2O and complete occupancy of the ferric on site by Fe(3+) and Al Optically, bendadaite is biaxial, positive, 2V(est) = 85+/-4 degrees, 2V(eale) = 88 degrees, with alpha 1 734(3). 13 1 759(3), 7 1 787(4) Pleochrosim is medium strong X pale reddish brown. Y yellowish brown, Z dark yellowish brown. absorption Z > V > X, optical dispersion weak, r > v. Optical axis plane Is parallel to (010), with X approximately parallel to a and Z nearly parallel to c Bendadaite has vitreous to sub-adamantine luster, is translucent and non-fluorescent It is brittle, shows irregular fracture and a good cleavage parallel to 1010} 3 15 0 10 g/cm(3), 3 193 g/cm3 (for the empirical formula) The five strongest powder diffraction lines [d in angstrom (I)(hkl] are 10 22 (10)(100), 7 036 (8)(110), 4 250 (5)(11 I), 2 865 (4)(311), 4 833 (3)(020,011) The d spacings are very similar to those of its Zn analogue, ojelaite The crystal structure of bendadaite was solved and refined using a crystal from the co-type locality with the composition (Fe(0 95)(2+)rectangle(0 05))(Sigma 1 00)(Fe(1 80)(3+)Al(0 20))Sigma(2 00)(As(1 48)P(0 52))(Sigma 2 00)O(8)) (OH)(2) 4H(2)O (R = 16%) and confirms an arthurite-type atomic arrangement

The new mineral santarosaite (IMA-CNMNC No. 2007-013) has the ideal chemical formula CuB2O4. It is tetragonal with space group I (4) over bar 2d. Cell parameters refined from X-ray powder diffraction data are a = 11.517(8), c = 5.632(6) (angstrom), V= 747(1) angstrom(3). Z = 12. The strongest reflections in the X-ray powder diffraction data are as follows d(obs.)(angstrom) (I, hkl): 3.797 (100, 211), 3.638 (47: 3 1 0) 2.775 (35 7 32 1) 2.572 (26, 420) and 2.501 (26, 411). Santarosaite was found in the Santa Rosa mine, which is located SE of the city of Iquique, Northern Chile. It occurs as vivid blue, vitreous globules up to 60 mu m in size. The blue globules are aggregates of tiny leaf-like crystallites less than 1 mu m thick. The calculated density is 3.96g/cm(3). The refractive index n derived from reflectance measurements is 1.75. Santarosaite is associated with atacamite, malachite, wulfenite and anhydrite. Chemical analyses gave (wt.%) CuO 43.24, PbO 4.48, CaO 0.97, B2O3 45.44. The resulting empirical formula based on 4 anions is (Cu0.86Pb0.03Ca0.02) B2.06O4. Due to voids in the crystal structure and the micro-crystallinity of the santarosaite globules the chemical analyses only add up to 94.13 wt.%. For structural reasons the chemical formula can thus be described as (Cu0.88Pb0.03Ca0.03 square(0.06))B2O4-0.06. The name of the new mineral is for the type locality, the Santa Rosa copper mine.

A method for the fabrication of bow-tie optical antennas at the apex of pyramidal Si3N4 atomic force microscopy tips is described. We demonstrate that these novel optical probes are capable of sub-wavelength imaging of single quantum dots at room temperature. The enhanced and confined optical near-field at the antenna feed gap leads to locally enhanced photoluminescence (PL) of single quantum dots. Photoluminescence quenching due to the proximity of metal is found to be insignificant. The method holds promise for single quantum emitter imaging and spectroscopy at spatial resolution limited by the engineered antenna gap width exclusively.

The new mineral sanromanite (IMA-CNMMN No. 2006-009) has the ideal chemical formula Na2CaPb3(CO3)(5). It is hexagonal with space group P6(3)mc. Unit cell data from single-crystal X-ray studies gave (angstrom) a = 10.570(1), c = 6.651 (1), V = 643.5(2) angstrom(3), Z = 2. Cell parameters refined from X-ray powder diffraction data are (angstrom) a = 10.553 (1), c = 6.641 (1), V = 640.5 (2) angstrom(3). Sanromanite is the Pb-dominant analogue of burbankite, calcioburbankite, and khanneshite. The strongest reflections in the X-ray powder diffraction data are as follows: (d(meas.),(angstrom) I, (hkl)): 3.769 (100, 20.1), 2.640 (65, 22.0), 3.066 (51, 21.1), 2.688 (50, 20.2), and 2.161 (50, 40.1). Sanromanite was found at the Santa Rosa mine near Iquique, Atacama desert, northern Chile. It occurs as radiating acicular or artichoke-like aggregates and as isolated needles. Fine needles appear colorless, aggregates show a greenish-yellow color. The calculated density is 5.20 g/cm(3). The mineral is optical negative with a calculated average refractive index of 1.822. Sanromanite is closely associated with malachite, calcite, anhydrite, chalconatronite, sodium-hydrogen carbonates and the recently described new mineral juangodoyite. Chemical analyses gave (wt.%) Na2O 6.04, CaO 5.64, PbO 65.86, CO2 (nom) 21.84, sum 99.38. The resulting empirical formula based on 15 anions is Na1.97Ca1.02Pb2.98C5.01O15. The name is for the Chilean naturalist (mineralogy and geology) FRANCISCO J. SAN ROMAN (1834-1902).

The emission of silver ions from the apex of an amorphous electrolyte tip has been investigated by field ion microscopy. The ion emission patterns show discrete nanometer-sized spots. We present evidence that they represent the termination of bulk ion conduction pathways at the solid-vacuum interface. The analysis of the signals from individual emission sites suggests the existence of a network of such pathways in the solid. Auto- and cross-correlation measurements of the currents from individual sites provide quantitative information on the microscopic dynamics of charge transport in solid electrolytes as well as on the lateral extent of the pathway network.

A bright ion source based on the solid electrolyte (AgI)0.5(AgPO3)0.5 has been developed. The solid electrolyte source provides stable currents of Ag+ in the microampere regime that make it suitable for focused ion beam applications. Similar conditions are expected for different solid electrolyte materials and their corresponding ions. This opens a broad field of applications in structuring and modifying devices on a nanometer scale using focused ion beams.

Suitably shaped metal nano structures act as resonant optical antennas that efficiently collect light and confine it to a subwavelength volume. Vice versa, light emission from nano volumes can be enhanced by coupling to antenna structures. We give a short introduction to antenna theory and discuss recent experiments that show the feasibility of achieving strong field enhancement using resonant dipole antennas for near infrared wavelengths. By scanning an optical antenna fabricated at the apex of an AFM tip over individual quantum dots, we observe enhanced emission of the latter while it is in close proximity of the antenna feed gap. Resonant optical antennas hold promise to be applied for spectroscopic characterization of nano structures with high spatial resolutions and single-molecule sensitivity.

The new mineral challacolloite has the ideal chemical formula KPb2Cl5. The type locality of challacolloite is the Challacollo silver mine SE of Iquique, Atacama desert, northern Chile. In the year of discovery challacolloite was also found on leucotephrite lava from the Vesuvius eruption of May 1855. It occurs closely associated with cotunnite as a hydrothermal phase (Chile) or as the product of fumarole activities (Italy). Challacolloite is colourless to white with an adamantine luster. Mobs's hardness is about 2-3. The calculated density is 4.77g/cm(3). Challacolloite is biaxial (+), 2 V-calc = 67 degrees with n alpha = 2.004 (2), n beta = 2.010 (2) and n gamma = 2.024 (3). Chemical analyses of the type material give (wt.%) K 5.45, Pb 66.30, Cl 28.69. Challacolloite is monoclinic with space group P2(1)/c. Cell parameters refined from powder diffraction data of the type material are a = 8.864 (8), b = 7.932 (8), c = 12.491 (11) (angstrom), beta = 90.153 (5)degrees, V = 878.2 (1) angstrom(3) with Z = 4. Challacolloite is isotypic with NH4Pb2Cl5 and PbU2Se5. Synthetic REE-doped equivalents of challacolloite are known as technical laser materials. The strongest reflections in the X-ray powder diffraction data of the type material are as follows [d(meas)(angstrom)(I, hkl)]: 3.686 (100, 211), 3.609 (49, 20-2), 2.669(42, 22-2), 8.855 (39, 100) and 3.961(31, 020). The mineral was named after its type locality.

The new mineral juangodoyite has the ideal chemical formula Na2Cu (CO3)(2). It is monoclinic with space group P2(1)/a. Cell parameters refined from X-ray powder diffraction data are (A) a = 6.171(4), beta = 8.171(5), c = 5.645 (4), b = 116.23 (2)degrees, V = 255.33 (15) angstrom(3), Z = 2. Juangodoyite is isostructural with synthetic sodium bis(carbonato)cuprate(II). The strongest reflections in the X-ray powder diffraction data are as follows: [d(meas.) (angstrom), I, (h k l)]: 2.666 (100, 11-2), 4.258 (75, 11-1), 5.056 (66, 001), 2.619 (65, 210) and 4.575 (57, 110). Juangodoyite was found at the Santa Rosa mine near Iquique, Atacama desert, northern Chile. It occurs as fine-grained pseudomorphs, with crystallites up to 5 mu m in size, after small laths of chalconatronite (Na2Cu(CO3)(2) center dot 3H(2)O). Its colour is a vivid ultramarine blue. The calculated density is 2.984 g/cm(3), the calculated average refractive index is 1.571. Juangodoyite is closely associated with chalconatronite, malachite, calcite, anhydrite and sodium hydrogen carbonates. Chemical analyses gave (wt.%) Na2O 28.27, CuO 33.77, CO2 38.45, sum 100.49. The resulting empirical formula calculated on the basis of 6 anions is Na2.08Cu0.98(C1.99O6).The mineral was named after Juan Godoy, discoverer of the Chanarcillo silver mine.

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The structure of potassium nitrate, KNO(3), has been redetermined at room temperature. The compound surprisingly shows a 2 x 2 x 1 superstructure and crystallizes in space group Cmc2(1). This result contrasts with that found in former investigations, which gave the supergroup Pmcn, neglecting the superstructure. The improved results are due to the employment of a CCD area detector.

This paper presents problems inherent to high-resolution near-field optical microscopy. It is shown on an easily understandable level, that high lateral confinement of optical fields (a prerequisite for high-resolution microscopy) leads to a fast decay of the fields. Consequently, the optical probe has to be brought very close to the sample surface, increasing the sensitivity to artifacts. Highly confined optical fields are strongly sensitive to variations in the probe–sample separation. The resulting optical images are, therefore, dominated by topographical variations and do not represent the optical properties of the sample surface.

In the following section, different mechanisms of light-induced changes of optical material properties are described. Often these changes are considered to be due to some specific material excitation (e.g., electron density, temperature). This is, however, a simplified description. In general, the material is excited in different ways and the various excitations are coupled. A separation of these excitation can be achieved, at last partially, by considering a short excitation pulse. Different excitations then develop at characteristic time ranges after the pulse.

Unprecedented optical image resolution (20 nm to 30 nm) has been obtained with a near-field optical scanner using light with a wavelength of half a micrometer. The key element is an extremely small aperture (∼10 nm) placed at the very top of a pyramidal screen. The aperture is scanned in the immediate proximity of the surface to be investigated, using vacuum tunneling to sense the distance. The am...