Search results for "Albite"
showing 10 items of 11 documents
Ferro-pedrizite, NaLi2(Fe2+ 2Al2Li)Si8O22(OH)2, a new amphibole-supergroup mineral from the Sutlug pegmatite, Tyva Republic, Russia
2015
Ferro-pedrizite, a new amphibole-supergroup mineral was discovered in the Sutlug pegmatite occurrence situated in the Targi River Basin, Tyva Republic, Eastern Sibera, Russia. The associated minerals are quartz, albite, microcline, spodumene, cassiterite, beryl, columbite-(Mn), fergusonite-β-(Y), fluorapatite, schorl, trilithionite and fluorite. Ferro-pedrizite forms dark grey-blue to violet-blue acicular and long prismatic crystals up to 2 × 5 × 50 mm and their aggregates. D meas = 3.16(1) g/cm3 (by hydrostatic weighing), 3.13(1) g/cm3 (by flotation in heavy liquids); D calc = 3.135 g/cm3. Ferro-pedrizite is optically biaxial (−), α = 1.614(3), β = 1.638(3), γ = 1.653(3), 2 V meas = 75(5)°…
On a peculiar metabasite in hercynian phyllites (sicily)
1976
On the basis of a mineralogical, petrological and chemical study of a “greenstone” complex intercalated in a phyllitic formation in the Western Peloritani Mountains, two main rock types can be distinguished: amphibole-chlorite metabasite (with traces of an old generation of glaucophane), and albite metabasite. The two rock types show considerable differences in composition, a consequence of sodium metasomatism. The study indicates that the greenstone complex is a metaspilite.
Quantification of minerals from ATR-FTIR spectra with spectral interferences using the MRC method.
2017
A method for quantifying the individual components of mineral samples based on attenuated total reflectance - Fourier transform infrared spectroscopy (ATR-FTIR) is described, extending the constant ratio (CR) method to analytes absorbing in a common range of wavenumbers. Absorbance values in the spectral region where the analytes absorb relative to the absorbance of an internal standard absorbing at a wavenumber where the analytes do not absorb, permits the quantification of N analytes using measurements at N fixed wavenumbers. The method was tested for mixtures of albite, orthoclase, kaolin and quartz.
Ice nucleation properties of the most abundant mineral dust phases
2008
[1] The ice nucleation properties of the nine most abundant minerals occurring in desert aerosols (quartz, albite, microcline, kaolinite, montmorillonite, illite, calcite, gypsum, and hematite) were investigated by environmental scanning electron microscopy (ESEM). In this instrument, the pure minerals are exposed to water vapor at variable pressures and temperatures. The crystallization of ice on the mineral particles is observed by secondary electron imaging, and the supersaturation for an activated particle fraction of 1–3% is determined as function of temperature. In all experiments, condensation of water prior to ice formation was not observed within detectable limits, even at water su…
?Short Distance?-Variabilit�t der Na-Gehalte niedrigmetamorpher mit Albit ber�hrungsparagenetisch koexistierender Hellglimmer
1973
White micas coexisting with albite, quartz, chlorite, and clinozoisite in low-grade schists of the Beaume Valley (Massif Central, France) have been analyzed by standard microprobe techniques. As the micas of an albite-rich thin section show significantly higher Na-contents than those of an albite-poor one of the same rock sample, the application of the muscovite-albite-geothermometer results in inconsistent temperature values. Thus the analyses may indicate that the distribution of sodium between coexisting white micas and albite not only depends on temperature and pressure but also on the chemical potentials of the alkalies in the metamorphic fluid phase.
Solubility of the assemblage albite+K-feldspar+andalusite+quartz in supercritical aqueous chloride solutions at 650 °C and 2 kbar
2003
Abstract The solubility of the high grade pelite assemblage albite+K-feldspar+andalusite+quartz at 650 °C and 2 kbar was determined in aqueous solutions over a total chloride range of 0.01–3 mCltot using rapid-quench hydrothermal technique. The concentration of Na, K, Si, and Al was determined in the fluid phase after quench. The K/Na ratio was determined by approaching the equilibrium from below and above. It is 0.34 at low chloride concentrations and decreases slightly to 0.31 with increasing total chloride. Silica and aluminum concentrations were determined only from undersaturation. The silica solubility is found to be independent of chloride concentration and is ∼0.13 molal. Aluminum i…
Experimental study on the solubility of the “model”-pelite mineral assemblage albite + K-feldspar + andalusite + quartz in supercritical chloride-ric…
2001
A total of 34 solubility experiments using the “model”-pelite mineral assemblage microcline + low albite + andalusite + quartz were performed at 600°C and 0.2 GPa over a total chloride range of 0.03–2.9 molal. The concentrations of sodium, potassium, aluminum, and silica were measured and the results are compared with four different thermodynamic datasets. The K/Na ratio was approached from below and above for the thermodynamically buffered mineral assemblage microcline + low albite + andalusite + quartz. Tight brackets were obtained for experiments performed in up to 1 molal chloride concentration. From 0.03 to ∼1 molal chloride concentration, a constant K/Na ratio of 0.33 was obtained. At…
Hydrothermal origin and age of jadeitites from Sierra del Convento Mélange (Eastern Cuba)
2012
Jadeitite (jadeite jade) from Sierra del Convento (eastern Cuba) occurs in a subduction-related serpentinite-matrix melange associated with a variety of high-pressure tectonic blocks including garnet-amphibolites and related anatectic trondhjemites. The eastern Cuban jadeitite is massive and characterized by rare quartz inclusions and omphacite exsolution in jadeite crystals, as well as replacement or infilling by omphacite. Minor minerals include epidote, biotite, albite, phengite, titanite, rutile, zircon, and apatite. Oscillatory zoning in jadeite crystals and zircon ages suggest hydrothermal crystallization in veins formed in serpentinized peridotite, probably of the mantle wedge. Al-Na…
Radial cracks around α-quartz inclusions in almandine: Constraints on the metamorphic history of the Oman mountains
1993
Radiating tensional cracks around α-quartz inclusions in almandine have been observed in metapelite samples from the southeastern Saih Hatat tectonic window, northeastern Oman Mountains. These almandines show an inclusion-rich (glaucophane + epidote) and strongly deformed core with inclusions of different mineral phases. The rim of the same almandines is inclusion-poor and shows only quartz, apatite, zircon, rutile and BaAl phosphates as inclusions. Quartz and apatite inclusions in the rim are single crystals often surrounded by radial cracks. These radial cracks developed during uplift by the dilation of α-quartz (4–5 vol%) without a phase transformation. Subsequently, these cracks were fi…
Microstructural and magnetic characterization of dusts from a stone crushing industry in Birbhum, India
2010
Abstract Stone dust sample collected from a stone crushing industry situated at Muhammad Bazar in Birbhum, India, is studied for its physical characterization using various techniques. Morphology and compositional analysis of the stone dust by scanning electron microscopy (SEM) reveal that the dust is an agglomeration of many tiny particles (0.32–2.12 μm), mostly having sharp edges, as well show microstructure heterogeneity. Elements present in the sample are detected by energy dispersive X-ray spectrometry (EDX). The X-ray diffraction (XRD) pattern analysis shows that the sample mainly contains minerals like anorthite, augite, esseneite and albite. An overall antiferromagnetic interaction …