Optical properties and unit cell parameters of nickel nitrate hexahydrate

1957 ◽  
Vol 45 (4) ◽  
pp. 263-267 ◽  
Author(s):  
A. Jayaraman
Keyword(s):  
Optical Properties ◽  
Unit Cell ◽  
Nickel Nitrate ◽  
Nitrate Hexahydrate ◽  
Unit Cell Parameters ◽  
Cell Parameters ◽  
Nickel Nitrate Hexahydrate

scholarly journals Mineralogy of the Vorontsovskoe gold deposit (Northern Urals). Part 4: Oxysalts

2021 ◽  
pp. 5-31
Author(s):  
A.V. Kasatkin ◽  
S.Yu. Stepanov ◽  
M.V. Tsyganko ◽  
R. Skoda ◽  
F. Nestola ◽  
...  
Keyword(s):  
Optical Properties ◽  
Chemical Composition ◽  
Gold Deposit ◽  
Russian Federation ◽  
Unit Cell ◽  
Unit Cell Parameters ◽  
Entire Series ◽  
Cell Parameters ◽  
Northern Urals

This is a fnal paper in a series of publications devoted to the mineralogy of the Vorontsovskoe gold deposit in the Northern Urals. The article reports on oxygen compounds (oxyhalides, oxides, hydroxides, carbonates, sulfates, tungstates, phosphates, arsenates and silicates) of the Vorontsovskoe deposit, their chemical composition and, for selected minerals, unit-cell parameters and optical properties. Armenite, claudetite, ramsdellite, hingganite-(Nd) and chapmanite are found for the frst time in Russian Federation. As a conclusion for the entire series of publications, the general features of mineralogy of the Vorontsovskoe deposit are discussed, thanks to which it is considered as a unique mineral locality not only in Urals but in general in Russia.

Some Observations on Igneous Ferrohastingsites

1963 ◽  
Vol 33 (263) ◽  
pp. 646-662 ◽  
Author(s):  
G. Borley ◽  
M. T. Frost
Keyword(s):  
Optical Properties ◽  
Chemical Composition ◽  
Unit Cell ◽  
Refractive Indices ◽  
Northern Nigeria ◽  
Unit Cell Parameters ◽  
Cell Parameters ◽  
Respective Parent ◽  
Parent Rocks ◽  
Southern Rhodesia

SummaryNine ferrohastingsites from the Younger Granites of Northern Nigeria and five from the nepheline-bearing rocks in the Marangudzi complex of Southern Rhodesia have been analysed chemically and their optical properties and unit-cell parameters determined.All the minerals have compositions that can be expressed by the formula NaCa2(Fe″Mg)4Fe‴Al2Si6O22(OH)2, but the Nigerian minerals differ from those of Marangudzi in their lower alumina contents, generally greater degree of iron enrichment, lower potassium, and more variable fluorine contents. These differences are considered to reflect the differences in composition of their respective parent rocks. The compositional similarities between some hastingsites and barkevikite are commented upon and the pleochroism of barkevikite is briefly discussed.Refractive indices of the analysed hastingsites have been plotted on the optical curves of Tröger. It is suggested that such curves are of limited use and that variations in unit-cell parameters might be a more useful method of determining the iron contents of hastingsites.The variation in cell parameters with variation in chemical composition of the analysed minerals is also discussed.

Chlorine-rich potassium hastingsite from West Ongul Island, Lützow–Holm Bay, East Antarctica

1987 ◽  
Vol 51 (363) ◽  
pp. 709-714 ◽  
Author(s):  
Kanenori Suwa ◽  
Masaki Enami ◽  
Tatsuro Horiuchi
Keyword(s):  
Optical Properties ◽  
Chemical Analysis ◽  
Unit Cell Volume ◽  
Granulite Facies ◽  
Total Iron ◽  
Unit Cell ◽  
East Antarctica ◽  
Unit Cell Parameters ◽  
Cell Parameters ◽  
Rock Types

AbstractChlorine-rich potassium hastingsite occurs in a calcareous pegmatite, a replacement zone and an amphibolite lens within hornblende gneiss on West Ongul Island, Lützow-Holm Bay, East Antarctica. The amphibolite lens and hornblende gneiss were metamorphosed to the kyanite-sillimanite grade of the granulite facies during Proterozoic metamorphism. Chemical analysis (3.27 wt.% Cl), unit cell parameters and optical properties of the Cl-rich potassium hastingsite are given. Cl-rich (> 3 wt.%) calcic amphiboles reported from various rock types are mostly more than 0.9 in (Na+ K) content, more than 0.4 in K/(Na + K) ratio, more than 0.75 in Fe2+/(Fe2++ Mg + Mn) ratio and more than 1.9 in AlIVcontent (total iron as FeO and O = 23). The unit cell volume of Cl-rich hastingsite is distinctly larger than that of Cl-poor hastingsite.

Kinematical and Dynamical CBED Pattern Models: Increasing the Accuracy of the Unit-Cell Parameter Measurements Based on CBED Patterns

1990 ◽  
Vol 48 (2) ◽  
pp. 540-541
Author(s):  
I.N. Yadhikov ◽  
S.K. Maksimov
Keyword(s):  
Reciprocal Lattice ◽  
Unit Cell ◽  
Reciprocal Lattice Vector ◽  
Unit Cell Parameters ◽  
Lattice Vector ◽  
Cell Parameters ◽  
Accuracy Of Measurements ◽  
The Difference ◽  
Image Position ◽  
Convergent Beam

Convergent beam electron diffraction (CBED) is widely used as a microanalysis tool. By the relative position of HOLZ-lines (Higher Order Laue Zone) in CBED-patterns one can determine the unit cell parameters with a high accuracy up to 0.1%. For this purpose, maps of HOLZ-lines are simulated with the help of a computer so that the best matching of maps with experimental CBED-pattern should be reached. In maps, HOLZ-lines are approximated, as a rule, by straight lines. The actual HOLZ-lines, however, are different from the straights. If we decrease accelerating voltage, the difference is increased and, thus, the accuracy of the unit cell parameters determination by the method becomes lower.To improve the accuracy of measurements it is necessary to give up the HOLZ-lines substitution by the straights. According to the kinematical theory a HOLZ-line is merely a fragment of ellipse arc described by the parametric equationwith arc corresponding to change of β parameter from -90° to +90°, wherevector, h - the distance between Laue zones, g - the value of the reciprocal lattice vector, g‖ - the value of the reciprocal lattice vector projection on zero Laue zone.

Sectioned rubisco crystals in TEM

1990 ◽  
Vol 48 (3) ◽  
pp. 664-665
Author(s):  
Gunnel Karlsson ◽  
Jan-Olov Bovin ◽  
Michael Bosma
Keyword(s):  
Plant Cell ◽  
Carbon Fixation ◽  
Unit Cell ◽  
Protein Crystals ◽  
Unit Cell Parameters ◽  
Cell Parameters ◽  
Photosynthetic Carbon Fixation ◽  
Photosynthetic Carbon

RuBisCO (D-ribulose-l,5-biphosphate carboxylase/oxygenase) is the most aboundant enzyme in the plant cell and it catalyses the key carboxylation reaction of photosynthetic carbon fixation, but also the competing oxygenase reaction of photorespiation. In vitro crystallized RuBisCO has been studied earlier but this investigation concerns in vivo existance of RuBisCO crystals in anthers and leaves ofsugarbeets. For the identification of in vivo protein crystals it is important to be able to determinethe unit cell of cytochemically identified crystals in the same image. In order to obtain the best combination of optimal contrast and resolution we have studied different staining and electron accelerating voltages. It is known that embedding and sectioning can cause deformation and obscure the unit cell parameters.

On the accuracy of determining the unit cell parameters of single crystals on modern laboratory diffractometers

2021 ◽  
Vol 62 (5) ◽  
Author(s):  
П.C. Серебренникова ◽  
В.Ю. Комаров ◽  
А.С. Сухих ◽  
С.А. Громилов
Keyword(s):  
Single Crystals ◽  
Unit Cell ◽  
Unit Cell Parameters ◽  
Cell Parameters

scholarly journals Crystal Structure Refinements of Four Monazite Samples from Different Localities

Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1028 ◽  
Author(s):  
M. Mashrur Zaman ◽  
Sytle M. Antao
Keyword(s):  
Crystal Structure ◽  
Electron Probe ◽  
Unit Cell Volume ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Large Unit Cell ◽  
A Site

This study investigates the crystal chemistry of monazite (APO4, where A = Lanthanides = Ln, as well as Y, Th, U, Ca, and Pb) based on four samples from different localities using single-crystal X-ray diffraction and electron-probe microanalysis. The crystal structure of all four samples are well refined, as indicated by their refinement statistics. Relatively large unit-cell parameters (a = 6.7640(5), b = 6.9850(4), c = 6.4500(3) Å, β = 103.584(2)°, and V = 296.22(3) Å3) are obtained for a detrital monazite-Ce from Cox’s Bazar, Bangladesh. Sm-rich monazite from Gunnison County, Colorado, USA, has smaller unit-cell parameters (a = 6.7010(4), b = 6.9080(4), c = 6.4300(4) Å, β = 103.817(3)°, and V = 289.04(3) Å3). The a, b, and c unit-cell parameters vary linearly with the unit-cell volume, V. The change in the a parameter is large (0.2 Å) and is related to the type of cations occupying the A site. The average <A-O> distances vary linearly with V, whereas the average <P-O> distances are nearly constant because the PO4 group is a rigid tetrahedron.

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