Chemical Constraints in Quantitative X-Ray Powder Diffraction for Mineral Analysis of the Sand/Silt Fractions of Sedimentary Rocks

1989 ◽  
pp. 489-496 ◽  
Author(s):  
D. K. Smith ◽  
G. G. Johnson ◽  
M. J. Kelton ◽  
C. A. Andersen
Keyword(s):  
Powder Diffraction ◽  
Sedimentary Rocks ◽  
Mineral Analysis ◽  
X Ray

Chemical Constraints in Quantitative X-ray Powder Diffraction for Mineral Analysis of the Sand/Silt Fractions of Sedimentary Rocks

1988 ◽  
Vol 32 ◽  
pp. 489-496 ◽  
Author(s):  
D. K. Smith ◽  
G. G. Johnson ◽  
M. J. Kelton ◽  
C. A. Andersen
Keyword(s):  
Diffraction Pattern ◽  
Powder Diffraction ◽  
Intensity Ratio ◽  
Sedimentary Rocks ◽  
Xrd Analysis ◽  
Mineral Analysis ◽  
X Ray ◽  
Unique Approach ◽  
Mineral Mixtures ◽  
Component Phase

AbstractQuantitative X-ray powder diffraction using the complete digitized diffraction pattern has proved to be an effective approach to improving the accuracy of the analysis of complex mineral mixtures, provided representative reference patterns and accurate Reference Intensity Ratio (RIR) factors arc available for each component phase. However, chemical and structural variability of common rock-forming minerals may complicate the pattern fitting approach. A method has been developed which utilizes X-ray fluorescence chemistry of an unknown and realistic compositional ranges for component phases as constraints on the quantitative XRD analysis without significant compromise of the pattern fit. This unique approach no only yields accurate weight fractions, but also provides indications of the specific compositions of each phase present in the mixture.

scholarly journals Fe-Al Phosphate Microcrystals in Pedogenic Goethite Pisoliths

Minerals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 357
Author(s):  
János Kovács ◽  
Éva Farics ◽  
Péter Szabó ◽  
István Sajó
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Fluorescence Spectroscopy ◽  
Powder Diffraction ◽  
Sedimentary Rocks ◽  
Depositional Environments ◽  
Substantial Contribution ◽  
Subtropical Climate ◽  
X Ray ◽  
Scanning Electron

In sedimentary rocks, Fe-Al phosphate minerals occur in different rocks and depositional environments. Herein, we present microcrystals of wavellite, crandallite, and cacoxenite from pedogenic goethite pisoliths and nodules. Pisoliths and nodules are generally dominated by Fe oxides and oxihydroxides. Frequently, pisoliths and nodules demonstrate high phosphatization and a substantial contribution of allogenic detritus. The aim of our study is to present these remarkable crystals found in goethites. We describe the geochemistry and mineralogy of the pisoliths and try to interpret the possible paragenesis of the minerals. Loose ferruginous pisoliths and nodules are separated from the red paleosol and analyzed using field emission scanning electron microscope (FE-SEM) coupled with the energy dispersive X-ray detector (EDS), X-ray fluorescence spectroscopy (XRF), and X-ray powder diffraction (XRD) methods. The studied paleosols are weathered in a subtropical climate and the newly formed precipitation products, such as crandallite, wavellite, cacoxenite, and goethite, accumulate during the weathering of apatite.

Direct Observation of Crystalline Ordering In Naturally Graphitized Carbon Produced by Low Grade Metamorphism

1977 ◽  
Vol 35 ◽  
pp. 162-163
Author(s):  
Thomas R. McKee ◽  
Peter R. Buseck
Keyword(s):  
Crystallite Size ◽  
Sedimentary Rocks ◽  
Carbonaceous Material ◽  
Low Grade ◽  
X Ray ◽  
Graphitized Carbon ◽  
Transmission Electron ◽  
Heat Treated ◽  
Commercial Carbon ◽  
Metamorphic Zone

Sediments commonly contain organic material which appears as refractory carbonaceous material in metamorphosed sedimentary rocks. Grew and others have shown that relative carbon content, crystallite size, X-ray crystallinity and development of well-ordered graphite crystal structure of the carbonaceous material increases with increasing metamorphic grade. The graphitization process is irreversible and appears to be continous from the amorphous to the completely graphitized stage. The most dramatic chemical and crystallographic changes take place within the chlorite metamorphic zone.The detailed X-ray investigation of crystallite size and crystalline ordering is complex and can best be investigated by other means such as high resolution transmission electron microscopy (HRTEM). The natural graphitization series is similar to that for heat-treated commercial carbon blacks, which have been successfully studied by HRTEM (Ban and others).

New horizons for the structural characterization of stainless steel slags by X-ray powder diffraction

2007 ◽  
Vol 2007 (suppl_26) ◽  
pp. 61-66 ◽  
Author(s):  
B. Peplinski ◽  
B. Adamczyk ◽  
G. Kley ◽  
K. Adam ◽  
F. Emmerling ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Powder Diffraction ◽  
Structural Characterization ◽  
X Ray ◽  
New Horizons

X-ray Structure Refinement and Vibrational Spectroscopy of Ca8Gd2 (PO4)6 O2

2013 ◽  
Vol 12 (10) ◽  
pp. 719-726
Author(s):  
R. Ayadi ◽  
Mohamed Boujelbene ◽  
T. Mhiri
Keyword(s):  
Solid State ◽  
General Formula ◽  
Vibrational Spectroscopy ◽  
Powder Diffraction ◽  
Infrared Spectra ◽  
Solid State Reaction ◽  
Structure Refinement ◽  
Unit Cell ◽  
Cell Group ◽  
X Ray

The present paper is interested in the study of compounds from the apatite family with the general formula Ca10 (PO4)6A2. It particularly brings to light the exploitation of the distinctive stereochemistries of two Ca positions in apatite. In fact, Gd-Bearing oxyapatiteCa8 Gd2 (PO4)6O2 has been synthesized by solid state reaction and characterized by X-ray powder diffraction. The site occupancies of substituents is0.3333 in Gd and 0.3333 for Ca in the Ca(1) position and 0. 5 for Gd in the Ca (2) position.  Besides, the observed frequencies in the Raman and infrared spectra were explained and discussed on the basis of unit-cell group analyses.

Application of X-ray tomography method for estimation of drilling agents influence on sedimentary rocks in the process of borehole drilling and completion

2020 ◽  
Vol 6 ◽  
pp. 40-44
Author(s):  
О.V. Garshina ◽  
◽  
D.А. Кazakov ◽  
I.L. Nekrasova ◽  
P.А. Khvoshchin ◽  
...  
Keyword(s):  
Sedimentary Rocks ◽  
X Ray ◽  
Borehole Drilling ◽  
Tomography Method
Sign in / Sign up

Export Citation Format

Share Document