A study of the neotocite group

1978 ◽  
Vol 42 (322) ◽  
pp. 279-280 ◽  
Author(s):  
A. M. Clark ◽  
A. J. Easton ◽  
M. Mount
Keyword(s):  
Room Temperature ◽  
Original Description ◽  
Refractive Indices ◽  
Magnesium Perchlorate ◽  
Type Specimens ◽  
Subsequent Work ◽  
X Ray ◽  
Conchoidal Fracture ◽  
Infra Red ◽  
Iron Bearing

SynopsesAn examination has been carried out of ten specimens assigned to the group. These include metatype specimens of neotocite (Gestrikland, Sweden) and penwithite (Wheal Owles, Penwith, Cornwall) and topo-type specimens of stratopeïte (Pajsberg, Sweden), klipsteinite (Herborn, Dillenberg, Germany), and opsimose (specimen labelled klipsteinite, but from Klapperud, Dalecarlia, Sweden). The investigation arose out of the recent find of neotocite at the Geevor mine, Cornwall, close to the site of the type locality for penwithite.In the investigation klipsteinite has been confirmed as a mixture (Fisher, 188o), the dominant mineral in the mixture giving an X-ray pattern close to birnessite. Chemical analyses, refractive indices, and specific gravity determinations are given for the remainder in the miniprint section, p. M27 (Table I). They show that the group can be represented fairly closely by the formula (Mn, Fe)SiO3.H2O, but with significant carbonate present in each sample. CO2 has not generally been reported before in these minerals and the water content is lower than previous analyses, as a result of the precautions taken in drying the material before analysis (over magnesium perchlorate at room temperature).The specimens examined are all dark brown or black in appearance (often darkening on exposure to light) with a vitreous lustre and conchoidal fracture. The group should be regarded as poorly crystalline since all the specimens gave similar X-ray powder patterns with three very broad and diffuse lines around 3·5, 2·6, and 1·6 Å respectively (see Whelan and Goldich, 1961). After heating to 1000 °C all form braunite, with the exception of stratopeite, which gave an X-ray powder pattern closer to pyroxmangite. Hausmannite or spinel were also found associated with braunite in several specimens.The full text includes the results of differential thermal analysis and infra-red spectra from the samples.Of the names used in the group, opsimose (Beudant, 1832) was the first recorded, but in this and the subsequent work of Bahr (1850), it was associated with material much richer in manganese. Wittingite and neotocite (Nordenskiöld, 1849) were -named separately on account of the higher iron content of neotocite. Stratopeïte (Igelström, 1851) is a magnesium-bearing variety, while penwithite (Collins, 1878, 1879) was thought to have a different manganese valency state from wittingite.In view of its current widespread usage and the fact that neotocite was originally named for an iron-bearing manganese silicate it is proposed that neotocite be defined as the group of poorly crystalline manganese silicates with formulae close to (Mn, Fe)SiO3.H2O and Mn > Fe. With Fe > Mn the series grades into hisingerite. Limited substitution of MgO, Al2O3, and CO2 should be acceptable. Finally it has been proposed that the other names be discarded. The Commission on New Minerals and Mineral Names, IMA, has approved these proposals, but came to no firm conclusion as to whether the group name should be spelt ‘neotocite’ or as in the original description ‘neotokite’. Accordingly either are permissible.

Electron Microscopy of Human Gallstones

1971 ◽  
Vol 29 ◽  
pp. 296-297
Author(s):  
C. Wolpers ◽  
R. Blaschke
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Bile Pigment ◽  
X Ray Diffraction ◽  
Triclinic Crystal System ◽  
X Ray ◽  
Follow Up Study ◽  
Infra Red ◽  
Main Components

Scanning microscopy was used to study the surface of human gallstones and the surface of fractures. The specimens were obtained by operation, washed with water, dried at room temperature and shadowcasted with carbon and aluminum. Most of the specimens belong to patients from a series of X-ray follow-up study, examined during the last twenty years. So it was possible to evaluate approximately the age of these gallstones and to get information on the intensity of growing and solving.Cholesterol, a group of bile pigment substances and different salts of calcium, are the main components of human gallstones. By X-ray diffraction technique, infra-red spectroscopy and by chemical analysis it was demonstrated that all three components can be found in any gallstone. In the presence of water cholesterol crystallizes in pane-like plates of the triclinic crystal system.

New data for lansfordite

1982 ◽  
Vol 46 (341) ◽  
pp. 453-457 ◽  
Author(s):  
R. J. Hill ◽  
J. H. Canterford ◽  
F. J. Moyle
Keyword(s):  
Absorption Spectrum ◽  
Low Temperature ◽  
Diffraction Pattern ◽  
Powder Diffraction ◽  
Room Temperature ◽  
X Ray ◽  
Infra Red ◽  
Bicarbonate Solutions

AbstractEuhedral crystals of the low-temperature mineral lansfordite, MgCO3 · 5H2O, have been prepared from saturated magnesium bicarbonate solutions at temperatures below 10°C. The crystals are monoclinic P21/a with a = 12.4758(7), b = 7.6258(4), c = 7.3463(6)Å, β = 101.762(6)°, V = 684.24Å3, Dcalc. = 1.693 g cm−3, Dobs. = 1.70(1) g m−3. At room temperature, the crystals slowly effloresce to produce pseudomorphs of nesquehonite, MgCO3 · 3H2O. Dehydration is complete at 300°C, with decarbonation taking place in the interval to 560°C. A new X-ray powder diffraction pattern is presented, and details of the infra-red absorption spectrum are discussed.

A tentative interpretation of the results of recent X-ray and infra-red studies of liquid water and H 2 O + D 2 O mixtures

1958 ◽  
Vol 247 (1251) ◽  
pp. 472-481 ◽  
Keyword(s):  
Liquid Water ◽  
Room Temperature ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
X Ray ◽  
Infra Red ◽  
Stretching Vibration ◽  
Density Of Water ◽  
Absorption Measurements ◽  
Melting Entropy

An idealized model is proposed for the arrangement of the molecules in liquid water which involves essentially a sixfold co-ordination of water molecules with four short OH...O hydrogen bonds of ~2.9 Å length and two long O...O contacts of ~3.6 Å length. An ice-like structure may contribute to a small extent also. This octahedral model has been based on evidence obtained from X-ray and infra-red absorption measurements. The model has been found to be in agreement with the density of water and the melting entropy of ice. The reliability of the radial distribution curves W(r) of liquid water obtained from recent X-ray diffraction measurements is discussed. Infra-red absorption measurements have been made of liquid HDO in excess D 2 O and H 2 O, respectively. The respective O—H and O—D stretching vibration frequencies of liquid HDO have been determined. The position (at 3400 cm -1 ) and shape of the relatively sharp single O—H stretching absorption band of liquid HDO is closely comparable to the corresponding band in liquid interbonding alcohols. The results of the infra-red studies indicate an OH...O distance of 2.86 Å in liquid water at room temperature.

scholarly journals EFFECT OF ETHANOL-WATER COMPOSITION ON CLINDAMYCIN HYDROCHLORIDE PSEUDOPOLYMORPHISM

2016 ◽  
Vol 8 (11) ◽  
pp. 269 ◽  
Author(s):  
Ilma Nugrahani ◽  
Silvana Anggraeni
Keyword(s):  
Room Temperature ◽  
Crystal Form ◽  
Recrystallization Process ◽  
Polarization Microscopy ◽  
X Ray ◽  
Water Composition ◽  
Infra Red ◽  
Long Time ◽  
Ethanol In Water ◽  
Original Crystal

Objective: Formation of clindamycin hydrochloride (clindamycin HCl) in monohydrate-ethanolate from the recrystallization process with ethanol–water (5:2) has been reported a long time ago. However, the effect of ethanol-water compositions into pseudo-polymorphism formation and its stability of was not reported yet. This study aimed to investigate the effect of ethanol-water proportion on the formation of clindamycin HCl-monohydrate and its ethanol solvate.Methods: Clindamycin HCl was recrystallized with the various percentages of ethanol. The fresh and after storage for 24 h at humidity and room temperature (25±2 °C, RH: 70±1%) crystals were characterized by FTIR (Fourier transform infra-red), PXRD (powder x-ray diffractometer), and DTA (differential scanning calorimeter). The study of desolvation/dehydration then was observed with a polarization microscopy-plate heater.Results: The results showed that monohydrate crystal was obtained from recrystallization in a concentration less than 50% ethanol in water. Next, the ethanolate was produced from the solvent of>70% ethanol. Meanwhile, the 50–70 % ethanol produced a hydrate–ethanolate, crystal, which has both hydrate and ethanol in its lattice. This hydrate-ethanolates was unstable, even in ambient temperature.Conclusion: Concentration of ethanol in water as the solvent will determine the clindamycin HCl pseudo polymorphism, which will back to its original crystal form by the time of storage.

scholarly journals Sieleckiite, a New Copper Aluminium Phosphate from Mt Oxide, Queensland, Australia

1988 ◽  
Vol 52 (367) ◽  
pp. 515-518 ◽  
Author(s):  
W. D. Birch ◽  
A. Pring
Keyword(s):  
Refractive Indices ◽  
South Australian Museum ◽  
Aluminium Phosphate ◽  
Type Specimens ◽  
Calculated Density ◽  
X Ray ◽  
Australian Museum ◽  
Simplified Formula ◽  
Measured Density ◽  
Mt Isa

AbstractSieleckiite is a new copper aluminium phosphate discovered at the Mt Oxide Copper Mine, 150 km north of Mt Isa, Queensland, Australia. It occurs with variscite, turquoise, libethenite and minor pseudomalachite in a fracture in a boulder of quartzite and shale. Sieleckiite forms deep sky blue to royal blue spheres up to 0.5 mm in diameter, made up of fibrous radiating crystals between 20 and 100 µm long and 1 to 2 µm wide. The mineral has a very pale blue streak and a pearly lustre on uneven fracture surfaces. Hardness is about 3 and the measured density is 3.02 g cm−3. The average of nine electron microprobe analyses gave CuO 32.39, Al2O3 26.57, P2O5 19.42%. Separate analyses gave H2O 18.1, CO2 1.6% (carbonate impurity). These data gave an empirical formula of Cu3.1Al4.0(PO4)2.1(OH)12.1.7H2O, calculated on the basis of 22 oxygen atoms. The simplified formula is Cu3Al4.0(PO4)2.1(OH)12.2H2O. The strongest lines in the X-ray powder diffraction pattern are {d(I)(hkl)}; 9.12(50)(100), 5.06(100)(101), 3.852(100)(111), 3.276(30)(2¯20), 2.827(50)(1¯02,102), 2.460(50)(3¯21). These data were indexed on a triclinic cell with a 9.41(8), b 7.56(5), c 5.95(6) Å, α 90.25(12)° β 91.27(12)° γ 104.02(7)° and a volume of 410.8(5) Å3. For Z = 1, the calculated density is 2.94 g cm−3. Optical properties could not be determined in full; the refractive indices are between 1.63 and 1.66, pleochroism is very weak from colourless to very pale blue.The mineral is named for the discoverer, Robert Sielecki (1958- ). Type specimens are preserved at the Museum of Victoria and the South Australian Museum. Sieleckiite was approved by the IMA Commission on New Minerals and Mineral Names prior to publication.

Dehydration Time Dependence on Piezoelectric and Mechanical Properties of Bovine Cornea

1999 ◽  
Vol 600 ◽  
Author(s):  
A. C. Jayasuriya ◽  
J. I. Scheinbeim ◽  
V. Lubkin ◽  
G. Bennett ◽  
P. Kramer
Keyword(s):  
Mechanical Properties ◽  
Hydrogen Bonding ◽  
Fourier Transform ◽  
Room Temperature ◽  
Piezoelectric Coefficient ◽  
Water Molecules ◽  
Wide Angle ◽  
X Ray ◽  
Mechanical Responses ◽  
Infra Red

AbstractThe Young's Modulus (E) and piezoelectric coefficient (d31) have been investigated as a function of dehydration time for bovine cornea at room temperature. The piezoelectric and mechanical responses observed were anisotropic for bovine cornea and d31 decreased, while E increased with dehydration. In addition, water molecules appear to increase the crystallinity (of collagen) in the cornea. With dehydration of the cornea, reduction of crystallinity and changes in hydrogen bonding were observed by Fourier Transform Infra Red (FTIR) and Wide Angle X-ray Diffracion (WAXD) measurements.

Voudourisite, Cd(SO4)·H2O, and lazaridisite, Cd3(SO4)3·8H2O, two new minerals from the Lavrion Mining District, Greece

2018 ◽  
Vol 83 (4) ◽  
pp. 551-559 ◽  
Author(s):  
Branko Rieck ◽  
Christian L. Lengauer ◽  
Gerald Giester
Keyword(s):  
Structure Type ◽  
Refractive Indices ◽  
Mining District ◽  
Chemical Compositions ◽  
Secondary Minerals ◽  
Space Group ◽  
X Ray ◽  
Conchoidal Fracture ◽  
Distinct Structure ◽  
Mohs Hardness

AbstractVoudourisite, Cd(SO4)·H2O, and lazaridisite, Cd3(SO4)3·8H2O, are two new minerals from the Esperanza Mine, Kaminiza Area, Lavrion Mining District, Greece. This small ancient mine is also the type locality of niedermayrite and katerinopoulosite. Further associated minerals are sphalerite, galena, edwardsite, chalcanthite, gypsum and greenockite. Both secondary minerals form tiny clusters or crusts and are among the latest to form in this paragenetic sequence. They are colourless or white, transparent to translucent, with a white streak and vitreous lustre. No fluorescence is observed. The minerals exhibit conchoidal fracture, no cleavage or preferred parting. The Mohs hardness is ~3 and both have brittle tenacity. Voudourisite is biaxial (–) with refractive indices at 589(1) nm of α = 1.580(2), β = 1.624(2), γ = 1.640(2), 2Vmeas. = 70(5)°, 2Vcalc. = 61° and β ~ || [010]. Lazaridisite is biaxial neutral with refractive indices at 589(1) nm of α = 1.552(2), β = 1.561(2), γ = 1.570(2), 2Vmeas. = 90(5)° and 2Vcalc. = 90°. The chemical compositions of voudourisite and lazaridisite are close to ideal with only minor amounts of copper detectable. The atomic arrangement in voudourisite (space group P21/c with a = 7.633(2), b = 7.458(2), c = 8.151(2) Å, β = 122.35(1)° and V = 392.0(2) Å3) is related to that of kieserite while lazaridisite (space group C2/c with a = 14.813(3), b = 11.902(2), c = 9.466(2) Å, β = 97.38(1)° and V = 1655.2(6) Å3) is a distinct structure-type. Calculated densities are 3.838 and 3.088 g/cm3, respectively.The strongest lines in the powder X-ray pattern [d in Å (I) (hkl)] are: 4.890 (66) (110); 3.741 (25) (020); 3.578 (100) (11$\bar 2$); 3.230 (43) (200); 2.525 (33) (022); 2.395 (29) (112) for voudourisite and 6.860 (100) (200); 6.317 (72) (111); 5.965 (84) (020); 4.512 (58) (310); 3.727 (78) (202); 3.608(82)(13$\bar 1$); 3.109 (83) (40$\bar 2$); 3.020 (50) (33$\bar 1$) for lazaridisite, respectively.

Chenite, Pb4Cu(SO4)2(OH)6, a new mineral, from Leadhills, Scotland

1986 ◽  
Vol 50 (355) ◽  
pp. 129-135 ◽  
Author(s):  
W. H. Paar ◽  
Kurt Mereiter ◽  
R. S. W. Braithwaite ◽  
Paul Keller ◽  
P. J. Dunn
Keyword(s):  
Powder Diffraction ◽  
Electron Microprobe ◽  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
Refractive Indices ◽  
New Mineral ◽  
Secondary Mineral ◽  
X Ray ◽  
Infra Red ◽  
The Ideal

AbstractChenite, a new lead-copper secondary mineral, has been found on specimens from the Leadhills area, Scotland. It is associated with caledonite, linarite, leadhillite, susannite, and other species, on oxidized galena with chalcopyrite. Electron microprobe analysis yielded PbO 74.5, CuO 7.8, SO3 13.3, H2O 4.4 (by difference), sum = 100 wt. %. The empirical formula (based on 14 oxygens) is Pb3.98Cu1.17S1.98O14H5.82; the ideal formula is Pb4Cu(SO4)2(OH)6, which requires PbO 75.2, CuO 6.7, SO3 13.5, H2O 4.6, sum = 100 wt. %.Infra-red spectroscopy showed the presence of only and OH− ions, with no H2O.Chenite is triclinic, P1 or P̄, with a = 5.791(1), b = 7.940(1), c = 7.976(1) Å, α = 112.02(1), β = 97.73(1), γ = 100.45(1)°, V = 326.0 Å3, Z = 1. The strongest lines in the X-ray powder diffraction pattern (d, I/Io, hkl) are: 5.55, 7, 100; 4.32, 6, 11; 3.60, 10 002; 3.41, 9, 10; 3.30, 5, 02; 3.00, 5, 111; 2.80, 7, 12; 2.07, 6, 211/21/13; 1.778, 5, 3/23.Chenite forms minute, singly terminated, transparent to translucent sky-blue crystals from 0.1 to over 1 mm long, elongated approximately [032]. Twenty different forms (pinacoids) have been identified on the four crystals studied. A good cleavage on {100}, and traces of a second on {001}, can be observed. Optically, chenite is biaxial negative, 2 V(measured) = 67±1°, 2 V(calc.) = 68° (Na). The refractive indices are α 1.871±0.005, β 1.909±0.005, γ 1.927±0.005 (Na). Dispersion is strong, r≫v. The mineral is weakly pleochroic. H (Mohs) ∼ 2½. D = 5.98, and calculated Dx = 6.044 g cm−3.

The unit cell and space-group of alamosite (PbSiO3)

1952 ◽  
Vol 29 (218) ◽  
pp. 933-935 ◽  
Author(s):  
A. L. Mackay
Keyword(s):  
Natural History ◽  
Chemical Analysis ◽  
British Museum ◽  
Original Description ◽  
Unit Cell ◽  
Refractive Indices ◽  
Space Group ◽  
X Ray ◽  
Ray Methods ◽  
Very High

Alamosite was first described by Palachc and Merwin, i who thought it might be isomorphous with wollastolfite. For that reason it has been re-examined, using X-ray methods.A specimen from the original locality at Alamos, Sonora, Mexico (B.M. 1910,330) was made available through the courtesy of the British Museum (Natural History), and in physical appearance it tallied with the original description. The crystals were aggregates of fibres arranged in bundles which cleaved perfectly perpendicular to the fibre axes. Small tablets could be readily cut out for X-ray analysis. The refractive indices were very high and the dispersion was large. As the axial ratios found by X-ray methods agreed with those given by Palache and Merwin, the latter's chemical analysis and density determination were not repeated.

The ageing of sesquioxide gels. II. Alumina gels

1962 ◽  
Vol 33 (257) ◽  
pp. 145-157 ◽  
Author(s):  
R. C. Mackenzie ◽  
R. Meldau ◽  
J. A. Gard
Keyword(s):  
Electron Microscope ◽  
Room Temperature ◽  
Aluminium Chloride ◽  
X Ray ◽  
High Ph ◽  
Ph Values ◽  
Gel Particles ◽  
Infra Red ◽  
Alumina Gels ◽  
Temperature Ageing

SummaryAluminium oxides occur widely in soils and are of considerable pedological significance. The ageing of alumina gels, prepared from aluminium chloride and ammonia, into crystalline hydroxides has been investigated using thermal, X-ray, infra-red, and electron-microscope techniques. At room temperature ageing is more rapid at high pH values. The structure of the original gel particles appears to resemble boehmite and ageing causes the formation of bayerite with small amounts of gibbsite. The morphology of the various mineral types is considered and a mechanism of ageing suggested.

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