alkali feldspar

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alkali feldspar

[′al·kə‚lī ′feld‚spar]
(mineralogy)
A feldspar composed of potassium feldspar and sodium feldspar, such as orthoclase, microcline, albite, and anorthoclase; all are considered alkali-rich.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
Zhu C, Lu P, Zheng Z, Ganor J (2010) Coupled alkali feldspar dissolution and secondary mineral precipitation in batch systems: 4.
Cayzer, "Alkali feldspar microtextures as provenance indicators in siliciclastic rocks and their role in feldspar dissolution during transport and diagenesis," Journal of Sedimentary Research, vol.
In terms of mineral composition, the granite consist of major felsic minerals: quartz (33 %), plagioclase (29 %) and alkali feldspar (27 %).
In fresh rocks Rb is concentrated in K-bearing silicates such as micas and alkali feldspar, thus producing high concentrations in the samples from Ormiston (K-feldspar) and Silverton (muscovite).
2002), incongruent weathering of alkali feldspar dissolves Na more rapidly than K (Lee and Parsons 1995), K-feldspar is more resistant than plagioclase (Nesbitt et al.
The tunnelling processes in alkali feldspars were separated, and the initial research was carried out by Visocekas et al.
Luminescence chronology of Pleistocene loess deposits from Romania: testing methods of age correction for anomalous fading in alkali feldspars. Quaternary Science Reviews, 22, 967-973.
Different aliquots were dated, and for the control quartz was used parallel to alkali feldspars. As a rule, the alkali feldspar measurements give somewhat higher ages than OSL from quartz, which can be explained by slower bleaching of the feldspar in the sunlight exposure.
Palaeodosimetrical properties of sodium alkali feldspars and problems of luminescence dating of sediments.
and Ribbe, P.H., 1987, Determining (Al,Si) distribution and strain in alkali feldspars using lattice parameters and diffraction-peak positions: A review, American Mineralogist, v.
The phenocrysts of plagioclase, hornblende, alkali feldspar and quartz are set in a felsophyric groundmass in a variable amount.