New data on wittichenite

1979 ◽  
Vol 43 (325) ◽  
pp. 109-113
Author(s):  
A. J. Criddle ◽  
C. J. Stanley
Keyword(s):  
Great Britain ◽  
Visible Spectrum ◽  
Type Locality ◽  
Published Data ◽  
Chemical Analyses ◽  
Reflected Light ◽  
Cell Dimensions

SummaryThe wittichenite (BM 1977, 172) discovered in the course of a reflected light study of polished sections from the Seathwaite deposit, Cumbria (described earlier in this journal by Stanley and Criddle), is the first authenticated occurrence of the species in Great Britain; for this reason it was examined in detail and compared with a specimen (BM 1437) from Wittichen, the type locality. Chemical analyses, cell dimensions, visible-spectrum reflectances, quantitative colour values, and VHN's are provided. They are in agreement with previously published data for the species.

Vymazalováite, Pd3Bi2S2, a new mineral from the Noril'sk-Talnakh deposit, Krasnoyarskiy region, Russia

2018 ◽  
Vol 82 (2) ◽  
pp. 367-373 ◽  
Author(s):  
Sergei F. Sluzhenikin ◽  
Vladimir V. Kozlov ◽  
Chris J. Stanley ◽  
Maria L. Lukashova ◽  
Keith Dicks
Keyword(s):  
Empirical Formula ◽  
Electron Back Scatter Diffraction ◽  
New Mineral ◽  
X Ray Diffraction ◽  
Average Composition ◽  
Reflected Light ◽  
Structural Identity ◽  
Cell Dimensions ◽  
Average Reflectance ◽  
Talnakh Deposit

ABSTRACTVymazalováite, Pd3Bi2S2 is a new platinum-group mineral discovered in the Komsomolsky mine of the Talnakh deposit, Noril'sk district, Russia. It forms small (from a few μm to 20–35 µm) inclusions or euhedral grains in intergrowths of polarite, sobolevskite, acanthite and unnamed (Pd,Ag)5BiS2 in aggregates (up to ~200 µm) in galena and rarely in chalcopyrite. It occurs with telargpalite, cooperite, braggite, vysotskite, sopcheite, stibiopalladinite, sobolevskite, moncheite, kotulskite, malyshevite, insizwaite, Au-bearing silver and the newly described mineral kravtsovite (PdAg2S) in association with pyrite, chalcopyrite and galena in vein-disseminated mineralization in skarn rocks. Synthetic vymazalováite is brittle; it has a metallic lustre and a grey streak. In plane-polarized reflected light, vymazalováite is creamy grey and appears slightly brownish against galena in the assemblage with chalcopyrite. It exhibits no internal reflections. Average reflectance values in air for natural and synthetic vymazalováite are (R natural, R synthetic in %) are: 46.35, 45.7 at 470 nm, 47.65, 47.45 at 546 nm, 48.5, 48.2 at 589 nm and 49.5, 49.0 at 650 nm. Seven electron probe micro-analyses of vymazalováite give an average composition: Pd 40.42, Bi 49.15, Ag 0.55, Pb 1.02, S 7.77 and Se 0.26, total 99.17 wt.%, corresponding to the empirical formula Pd3.05(Bi1.89Ag0.04Pb0.04)Σ1.97(S1.95Se0.03)Σ1.98 based on a total of 7 atoms per formula unit. The simplified formula is Pd3Bi2S2. The mineral is cubic, space group I213, with a = 8.3097(9) Å, V = 573.79(1) Å3 and Z = 4. The density calculated on the basis of the empirical formula and cell dimensions of synthetic vymazalováite is 9.25 g/cm3. The strongest lines in the powder X-ray diffraction pattern of synthetic vymazalováite [d in Å (I) (hkl)] are: 4.15(32)(200), 2.93(78)(220), 2.40(100)(220), 2.08(53)(400), 1.695(34)(422), 1.468(35)(440) and 1.252(31)(622). The structural identity of natural vymazalováite with synthetic Pd3Bi2S2 was confirmed by electron back-scatter diffraction measurements on the natural sample. This new mineral honours Dr Anna Vymazalová of the Czech Geological Survey, Prague.

The chemistry and cell parameters of omphacites and related pyroxenes

1969 ◽  
Vol 37 (285) ◽  
pp. 61-74 ◽  
Author(s):  
A. D. Edgar ◽  
A. Mottana ◽  
N. D. Macrae
Keyword(s):  
Powder Diffraction ◽  
Electron Microprobe ◽  
Graphical Representation ◽  
Chemical Compositions ◽  
Chemical Analyses ◽  
X Ray ◽  
Cell Parameters ◽  
Cell Dimensions ◽  
Approximate Estimation

SummaryIn an attempt to correlate the chemical compositions and cell sizes of omphacites and related pyroxenes, the cell dimensions of fifty-five analysed pyroxenes have been determined, or taken from the literature. Twenty-two of the chemical analyses are new, nineteen of them being done by electron microprobe. Approximately two-thirds of the total number of analyses may be considered first class, the remainder are of doubtful or unknown quality. Cell parameters, determined by X-ray powder diffraction methods, have errors of 0·1 % for the majority of samples, although for some samples taken from the literature errors are unknown.The majority of methods of recalculating omphacite analyses into their end-member molecules are unsuitable for correlation of cell constants with chemistry, mainly due to the impossibility of graphical representation of more than three end-member molecules, and to the non-stoichiometry of these molecules. Using a modification of Tröger's (1962) method of recalculating chloromelanite analyses the present analyses have been recalculated into the diopside-jadeite-acmite and diopside-jadeite-hedenbergite molecules and compared with their determined cell parameters. Because of the gradations in all parameters between these end-member molecules, determination of compositions based on the cell parameters (a, b, c, vol, or β) can only be made within wide limits. However, using a method of projection of compositions from the acmite and hedenbergite apices to the diopside-jadeite join the ratios of diopside to jadeite can be determined for most samples to within ±5 mol%. As there are the most important constituents of most omphacites, this method permits an approximate estimation of omphacite compositions. From a knowledge of the cell sizes of the omphacite a rough indication of the conditions of formation of its host rock may also be obtained.

Palladium arsenide-antimonides from habira, Minas Gerais, Brazil

1974 ◽  
Vol 39 (305) ◽  
pp. 528-543 ◽  
Author(s):  
A. M. Clark ◽  
A. J. Criddle ◽  
E. E. Fejer
Keyword(s):  
Minas Gerais ◽  
Powder Pattern ◽  
Weak Anisotropy ◽  
Yellow Colour ◽  
Space Group ◽  
Pale Yellow Colour ◽  
Reflected Light ◽  
Cell Dimensions ◽  
Polysynthetic Twinning ◽  
Reflectance Measurements

SummaryThe arsenopalladinite concentrates from Itabira, Minas Gerais, Brazil, have been found to contain three arsenide-antimonides of palladium, namely arsenopalladinite, atheneïte, and isomertieite. The second and third of these are new minerals.Arsenopalladinite, redefined, is Pd5(As,Sb)2 and triclinic with a 7·399, b 14·063, c 7·352 Å, α 92° 03′, β 118° 57′, γ 95° 54′. Z = 6. Dmeas = 10·4, Dcalc = 10sd46. In reflected light arsenopalladinite is white with a yellowish creamy hue. The mineral shows complex polysynthetic twinning and is strongly anisotropic. Reflectance measurements at 470, 546, 589, and 650 nm respectively gave: in air, 46·67–48·86, 49·97–52·90, 52·82–54·96, and 55·61–57·72 in oil, 32·30–35·07, 37·12–39·40, 38·97–41·32, and 40·28–43·07. VHN100 379–449, av. 407.Atheneïte, (Pd, Hg)3As, is hexagonal, space group P6/mmm and cell dimensions a 6·798, c 3·483 Å. The strongest lines of the powder pattern are 2·423 vvs (111) , 2·246 vs (201), 1·371 s (212), 1·302 s (302), 1·259 s (321). Z =2. Dcalc = 10·16. In reflected light atheneïte is white with a faint bluish tint compared to arsenopalladinite. Anisotropy distinct. Untwinned. Reflectivities for the two grains examined are: in air, 470 nm 47·51–54·75, 47·43–51·18; 546 nm 50·79–58·01, 51·36–54·36; 589 nm 53·13–61·01, 53·24–55·86; 650 nm 55·94–63·13, 54·76–56·77; in oil, 470 nm 30·03–43·67, 33·46–37·31; 546 nm 33·42–47·75, 37·64–41·07; 589 nm 35·80–49·04, 39·40–42·24; 650 nm 38·25–50·49, 41·07–42·85. VHN100 419–442, av. 431.Isomertieite, (Pd,Cu)5(Sb,As)2, is cubic, space group Fd3m, a 12·283 Å. The strongest lines of the powder pattern are 2·356 vs (333, 511), 2·167 vvs (440), 0·8599 s (10.10.2, 14.2.2), 0·8206 s (12.8.4), 0·7996 s (10.10.6, 14.6.2), 0·7881 s (999, 1.11.1, 13·7·5, 15·3·3), 0·7801 s (12.10.2, 14.6.4). Z = 16. Dcalc = 10·33. In reflected light isomertieite is a pale yellow colour. One grain was isotropic, three others displayed weak anisotropy. Untwinned. Reflectance measurements at 470, 546, 589, and 650 nm gave respectively: in air, 44·74–46·46, 52·23–53·25, 55·05-57·49, 56·97–62·03; in oil, 31·04–31·40, 38·42–38·90, 40·80–42·16, and 42·91–45·63. VHN100 587–597, av. 592.Quantitative colour values are also given, and the chemical and optical properties are compared with the related mineral, stibiopalladinite.

Feinglosite, a new mineral related to brackebuschite, from Tsumeb, Namibia

1997 ◽  
Vol 61 (405) ◽  
pp. 285-289 ◽  
Author(s):  
A. M. Clark ◽  
A. J. Criddle ◽  
A. C. Roberts ◽  
M. Bonardi ◽  
E. A. Moffatt
Keyword(s):  
Visible Spectrum ◽  
New Mineral ◽  
Monoclinic Space Group ◽  
Indentation Hardness ◽  
Calculated Density ◽  
Reflected Light ◽  
The Mean ◽  
Micro Indentation ◽  
Reflectance Data ◽  
The Ideal

AbstractFeinglosite, the zinc analogue of arsenbrackebuschite, was found lining a cavity in a sample of massive chalcocite from Tsumeb, Namibia. In this cavity it is associated with wulfenite, anglesite and goethite. The mean of seven electron-microprobe analyses (wt.%) is: PbO 61.4, ZnO 7.3, FeO 1.8, As2O5 22.1, SO3 5.3, H2O (by difference) [2.1], total = [100.00]%, leading to the ideal formula: Pb2(Zn,Fe)[(As,S)O4]·H2O. Feinglosite is monoclinic, space group P21 or P21/m, a 8.973(6), b 5.955(3), c 7.766(6) Å, β 112.20(6)°, with Z = 2. The strongest five reflections of the X-ray powder diffraction pattern are [d in Å (I) (hkl)]: 4.85 (50) (110), 3.246 (100) (112), 2.988 (60) (301), 2.769 (60) (300/211), 2.107 (50) (321). The mineral is pale olive-green, transparent, sectile, and has a white streak and adamantine lustre. It overgrows clusters of goethite crystals and forms globular microcrystalline aggregates up to 0.5–0.75mm in size. The hardness on Mohs' scale is 4–5: the mean micro-indentation hardness is 263 at VHN100. Its calculated density is 6.52 g cm−3. The mineral is pale brownish grey in reflected light (when compared with goethite). Visible spectrum reflectance data are presented. Feinglosite is named for Mark N. Feinglos who first recognised the mineral on a specimen in his collection.

scholarly journals On the structure and petrography of the Ipernat Dome, western Greenland

1964 ◽  
Vol 46 ◽  
pp. 1-88
Author(s):  
R Lauerma
Keyword(s):  
Aerial Photographs ◽  
Chemical Analyses ◽  
Gneiss Dome ◽  
Exposed Area ◽  
Cell Dimensions ◽  
Geological Map ◽  
Map Scale ◽  
Unit Cell Dimensions ◽  
Sodium And Potassium ◽  
Representative Samples

A well exposed area with a Precambrian gneiss dome was investigated. Photogeological methods were used to a great extent; the aerial photographs are reproduced and a geological map, scale 1:75000, is presented. The folding appears to be rather gentle. For the greatest part the rocks crystallized under the conditions of hornblende-granulite subfacies. Subsequently, a large proportion of them metamorphosed retrogressively. Chemical analyses of three granodioritic and quartz dioritic rocks and one garnet are presented. Refraction indices and unit cell dimensions of three garnets, optical properties of some pyroxenes and triclinicity values of some potash feldspars are given. Twenty determinations of the sodium and potassium content of representative samples indicate that potassium is not concentrated in the gneiss core of the dome.

X-Ray data and chemical analyses of some titanomagnetite and ilmenite samples from the Bushveld Complex, South Africa

1972 ◽  
Vol 38 (299) ◽  
pp. 863-871 ◽  
Author(s):  
T. C. Molyneux
Keyword(s):  
Bushveld Complex ◽  
Coarse Grained ◽  
Chemical Analyses ◽  
Skaergaard Intrusion ◽  
Average Cell ◽  
Cell Parameters ◽  
A Value ◽  
Cell Dimensions ◽  
Powder Samples ◽  
Layered Sequence

SummaryThe cell dimensions of powder samples of some Bushveld titanomagnetites and ilmenites were determined using a 114·6 mm AEG Guinier camera. The average cell dimension of the titanomagnetite is 8·400±0·005 Å and there is no definite relationship between the cell edge of the samples and their position in the layered sequence. The average cell parameters of coarse-grained ilmenite are a 5·085±0·005 Å and c 14·09±0·02 Å. Ilmenite that has replaced ulvöspinel has on average a value of some 0·003 Å greater than that of associated coarse ilmenite grains.Chemical analyses indicate that titanomagnetite from pegmatoidal plugs and from the top of layered sequence was generally subject to late-stage magmatic alteration and hence lies in the Titanomagnetite II field. In the Bushveld Complex there is an increase in the TiO2 content of titanomagnetite from some 12 % at the base to 18 % at the top of the Upper Zone. However, Bushveld titanomagnetite tends to be poorer in TiO2 than similar samples from the Skaergaard intrusion.A discrepancy between modal and normative hercynite in the Bushveld samples indicates that a considerable amount of hercynite is probably still in solid solution in the titanomagnetite.Chemical analyses of Bushveld ilmenites reveal that they lie in the same tholeiitic field as those of the Skaergaard intrusion.

Zr-rich garnet and Zr- and Th-rich perovskite from the Polino carbonatite, Italy

1992 ◽  
Vol 56 (385) ◽  
pp. 581-586 ◽  
Author(s):  
L. Lupini ◽  
C. T. Williams ◽  
A. R. Woolley
Keyword(s):  
Strong Correlation ◽  
Type Locality ◽  
Published Data ◽  
Site Distribution ◽  
Tetrahedral Sites

AbstractTh- and Zr-bearing perovskite and Zr-rich Ti garnet are described from the Polino calcite carbonatite, Italy. The garnets contain 6.05-7.50 wt.% ZrO2 in cores and up to 15.80 wt.% in rims. Silicon is low in these garnets and substantial Al and Fe 3+ has been assigned to the tetrahedral sites. A strong correlation of Si with Zr from published data suggests the possibility that some Zr may also be tetrahedrally coordinated. However, the chemistry alone does not constrain the site distribution of Fe, Ti, Zr and Mg unambiguously. The perovskites are very unusual in containing 2.81-3.27 wt.% ZrO2 and 1.48-1.71 wt.% ThO2. For comparison, new analyses are presented of the zirconium garnet kimzeyite and coexisting perovskite from the type locality at Magnet Cove.

Plumbian tennantite from Sark, Channel Islands

1977 ◽  
Vol 41 (317) ◽  
pp. 59-63 ◽  
Author(s):  
A. C. Bishop ◽  
A. J. Criddle ◽  
A. M. Clark
Keyword(s):  
Powder Diffraction ◽  
Electron Probe ◽  
Visible Spectrum ◽  
Channel Islands ◽  
Electron Probe Analysis ◽  
X Ray ◽  
Probe Analysis ◽  
Cell Dimensions ◽  
Reflectance Data

SummaryAn unusual tennantite, containing 4·64% Pb, has been found on a mineral specimen from Sark's Hope Mine collected in 1843. An electron-probe analysis is given, together with visible spectrum reflectance data, quantitative colour values, VHN, and cell dimensions determined from X-ray powder diffraction photographs.

Multiprobe End-Point Detection for Precision Control of the Copper CMP Process

2001 ◽  
Vol 671 ◽  
Author(s):  
Thomas Laursen ◽  
Malcolm Grief
Keyword(s):  
Small Diameter ◽  
Visible Spectrum ◽  
Wafer Surface ◽  
Endpoint Detection ◽  
Reflected Light ◽  
End Point Detection ◽  
Copper Cmp ◽  
Time Basis ◽  
Point Detection ◽  
Large Representative

ABSTRACTSentinelä is an optical multiprobe endpoint detection (EPD) system that has been developed by SpeedFam-IPEC (SFI) for the 200-mm and 300-mm Momentum orbital polishers. Sentinel EPD for copper CMP is based on monitoring the visible spectrum of light from a Xenon (Xe) flash lamp, which has been reflected by the wafer surface during polish. Large representative areas of the wafer are monitored from multiple locations in the pad continuously throughout the polish process. Spectra of reflected light from cleared and uncleared copper on a pattern wafer demonstrate a clear transition from copper to the underlying dielectric layer.With the Sentinel EPD system, the wafer is probed at optimized multiple locations constantly throughout the polish process by small-diameter light spots. The coverage of the monitoring is extensive and the radial coverage is substantial on a real-time basis. The EPD call is made based on an EPD signal, which displays the fractional copper coverage as a function of polish time. The detection of copper clearing on the SFI Momentum tools is very reliable and predictable, and not sensitive to process changes.

scholarly journals Micro-Actuated Tunable Hierarchical Silver Nanostructures to Measure Tensile Force for Biomedical Wearable Sensing Applications

Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 476
Author(s):  
Yong Ho Kwon ◽  
Jayer Fernandes ◽  
Jae-Jun Kim ◽  
Jiangang Chen ◽  
Hongrui Jiang
Keyword(s):  
Data Transfer ◽  
Tensile Force ◽  
Wearable Sensors ◽  
Visible Spectrum ◽  
Blue Shift ◽  
Photonic Devices ◽  
Silver Nanostructures ◽  
Sensing Applications ◽  
Design Flexibility ◽  
Reflected Light

Commercially available biomedical wearable sensors to measure tensile force/strain still struggle with miniaturization in terms of weight, size, and conformability. Flexible and epidermal electronic devices have been utilized in these applications to overcome these issues. However, current sensors still require a power supply and some form of powered data transfer, which present challenges to miniaturization and to applications. Here, we report on the development of flexible, passive (thus zero power consumption), and biocompatible nanostructured photonic devices that can measure tensile strain in real time by providing an optical readout instead of an electronic readout. Hierarchical silver (Ag) nanostructures in various thicknesses of 20–60 nm were fabricated and embedded on a stretchable substrate using e-beam lithography and a low-temperature dewetting process. The hierarchical Ag nanostructures offer more design flexibility through a two-level design approach. A tensional force applied in one lateral (x- or y-) direction of the stretchable substrate causes a Poisson contraction in the other, and as a result, a shift in the reflected light of the nanostructures. A clear blue shift of more than 100 nm in peak reflectance in the visible spectrum was observed in the reflected color, making the devices applicable in a variety of biomedical photonic sensing applications.

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