alkali feldspar

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alkali feldspar

n.
Any of a series of feldspars, consisting primarily of a mixture of sodium aluminum silicate, NaAlSi3O8, and potassium aluminum silicate, KAlSi3O8.
References in periodicals archive ?
Alkali feldspars are generally altered to sericite.
Phenocrysts of plagioclase and hornblende along with alkali feldspar, quartz and ores are embedded in felsophyric groundmass.
Alkali feldspars are represented by orthoclase and microcline.
In terms of mineral composition, the granite consist of major felsic minerals: quartz (33 %), plagioclase (29 %) and alkali feldspar (27 %).
Alkali feldspars are extensively used as palaeodosimeters for dating Quaternary deposits.
The tunnelling processes in alkali feldspars were separated, and the initial research was carried out by Visocekas et al.
Plagioclase dramatically removes Sr at intermediate stages and alkali feldspars sequester Ba and Rb as late-stage trachytes and phonolites form in alkaline magmas.
1987, Determining (Al,Si) distribution and strain in alkali feldspars using lattice parameters and diffraction-peak positions: A review, American Mineralogist, v.
In rock-forming minerals, K commonly resides in alkali feldspars and micas, while U and Th reside in monazite, xenotime, zircon, and various oxides (Dickson and Scott 1997).
The study of the efficiency of (optical) response by stimulation means the measurements of the OSL stimulation spectra of quartz and alkali feldspars in the widest possible spectral region.