A Study on Color Stones of Clay Minerals — Changhua Stone

2011 ◽  
Vol 492 ◽  
pp. 404-409
Author(s):  
Yan Fang Chen ◽  
Xue Hui Yu

Changhua Stone is a rock, composed of clay minerals such as dickites and is also a special secondary quartzite formed by gas liquid metasomatic metamorphism. The article emphasizes its study on rock characteristics, mineral composition, and the causes of formation of Changhua Stone, excluding Changhua Chicken-Blood Stone. By observing petrographical characters of Changhua Stone, analyzing its physical and chemical characters, and testing its geochemical compositions with SEM and X-ray diffraction analysis, the results indicate that the mineral compositions of Changuan Stone are relate to the composition of protolith, the compositions and characters of metasomatic metasomatic fluid, and the conditions of metamorphism, especially the stress and the temperature.

1962 ◽  
Vol 42 (2) ◽  
pp. 296-301 ◽  
Author(s):  
J. S. Clark ◽  
J. E. Brydon ◽  
H. J. Hortie

X-ray diffraction analysis was used to identify the clay minerals present in fourteen subsoil samples that were selected to represent some more important clay-bearing deposits in British Columbia. The clay mineralogy of the subsoils varied considerably but montmorillonitic clay minerals tended to predominate in the water-laid deposits of the south and illite in the soil parent materials of the Interior Plains region of the northeastern part of the Province.


Clay Minerals ◽  
1967 ◽  
Vol 7 (1) ◽  
pp. 79-90 ◽  
Author(s):  
Ronald J. Gibbs

AbstractIn the quantitative X-ray diffraction analysis of a series of samples, the problems arising from the variable compositions and degrees of crystallinity of clay minerals were overcome to a great extent by the use of standards extracted from the samples. Procedures are given for separation of the montmorillonite standard by differential settling of Na-montmorillonite solvated in an ethanol solution and for isolation of the kaolinite, mica, and chlorite standards by density separation of their Na-forms in thallous formate.Calibration curves were prepared from the X-ray diffractograms obtained for series of known mixtures of Ca-forms of the standards and the internal standard boehmite using both powder and smear-oriented mounting techniques.


1974 ◽  
Vol 39 (3) ◽  
pp. 477-483 ◽  
Author(s):  
Wayne C. Isphording

AbstractThe identification of the original paste and temper minerals present in ceramicware fragments can often be useful in determining if the fragments are indigenous to the area or whether they represent tradeware. To date, it has generally been believed that no certain means existed to identify the mineral constitutents once they were destroyed in the original kiln-firing operation. A new technique is described that permits the investigator to often identify both temper and the fine-grained paste materials as well. This method involves: (1) crushing the fragment to a fine powder; (2) heating the powder in a high temperature furnace to sufficient temperatures to cause the constituent ions present to recombine to form new, high temperature minerals; and (3) X-ray diffraction analysis to identify the new minerals. In many cases, identification of the resulting high temperature minerals will clearly indicate the composition of the original clay paste and temper. Examples are shown for the clay minerals kaolinite, montmorillonite and palygorskite. Diffractograms are also presented for comparison of ceramic fragments from Mexico and Alabama that contain the above minerals as original constituents.


1993 ◽  
Vol 58 (12) ◽  
pp. 2924-2935 ◽  
Author(s):  
Jane H. Jones ◽  
Bohumil Štíbr ◽  
John D. Kennedy ◽  
Mark Thornton-Pett

Thermolysis of [8,8-(PMe2Ph)2-nido-8,7-PtCB9H11] in boiling toluene solution results in an elimination of the platinum centre and cluster closure to give the ten-vertex closo species [6-(PMe2Ph)-closo-1-CB9H9] in 85% yield as a colourles air stable solid. The product is characterized by NMR spectroscopy and single-crystal X-ray diffraction analysis. Crystals (from hexane-dichloromethane) are monoclinic, space group P21/c, with a = 903.20(9), b = 1 481.86(11), c = 2 320.0(2) pm, β = 97.860(7)° and Z = 8, and the structure has been refined to R(Rw) = 0.045(0.051) for 3 281 observed reflections with Fo > 2.0σ(Fo). The clean high-yield elimination of a metal centre from a polyhedral metallaborane or metallaheteroborane species is very rare.


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