BACKGROUND Determination of quartz by Fourier transform infrared spectrometry (FTIR) is not specific: the obtained results are influenced by matrix components, some of which cause spectral interference. The aim of the study was to evaluate the effect of dust components responsible for spectral interference with quartz on the results of its determinations, and to develop methods to minimize the ...

AIMS To reanalyse exposure-response data from a Scottish colliery to gain a more detailed knowledge of the relations between exposure to quartz and risks of silicosis in coal miners, and hence inform the debate on an appropriate occupational standard for respirable quartz. METHODS Detailed data on working times at different quartz concentrations were combined to produce exposure profiles for ...

We present thermodynamic estimates of pressures, temperatures, and volatile activities in vailably deformed, gabbroic to granitic, Cretaceous (115-100 Ma) batholithic and framework rocks of the Tehachapi Mountains, southernmost Sierra Nevada, California. A1 contents of hornblende in granitoids imply igneous emplacement at --8 kbar in the southernmost Tehachapi Mountains, with lower pressures (3...

The copper–gold ores of the Moonta mineral field, in the eastern part of the Archaean–Mesoproterozoic Gawler Craton, South Australia, are vein deposits occupying fractures and shear zones within the Palaeoproterozoic Moonta Porphyry. The veins show a spatial relationship with Mesoproterozoic granites, equivalents of the Hiltaba Suite granites that are widespread in the Gawler Craton. The ores w...

A further comparison of the Health and Safety Executive (HSE) standard quartz, A9950 (Sikron F600), and the National Institute of Standards and Technology (NIST) Standard Reference Material (SRM) 1878, standard respirable alpha-quartz, has been carried out for the four principal diffraction peaks. In the earlier comparison by Jeyaratnam and Nagar (1993, Ann Occup Hyg; 37: 167-79), the standards...

The X-ray diffraction method and the phosphoric acid method are widely used to determine the fraction of free silica (mainly quartz and other silica polymorphs) in respirable dust sampled in working environments in Japan. In this study, we clarified the size effect of quartz dust for the X-ray diffraction method and the phosphoric acid method using size controlled quartz samples. The quartz sam...

introduction the area of this study is located near hamadan within the sanandaj - sirjan tectonic zone. in the hamadan area, consisting mainly of mesozoic plutonic and metamorphic rocks, aplites and pegmatites locally contain garnets.(baharifar et al., 2004, amidi and majidi, 1977; torkian, 1995. garnet-bearing schists and hornfelses in the area are products of regional metamorphism shown by sl...

molybdenite occurs in five forms in the sar cheshmeh porphyry copper deposit, namely, (1)-veinlets with quartz-molybdenite, (2)-veinlets with quartz-molydenite that were filled with pyrite, (3)-veinlets with quartz-molybdenite-pyrite–chalcopyrite, (4)-molybdenite veinlets with very low quartz and (5)-disseminated molybdenite grains. because of their large size, the veinlet-related molybdenite g...