sanidine

American  

[san-i-deen, -din] / ˈsæn ɪˌdin, -dɪn /

noun

Mineralogy.

1. a glassy, often transparent variety of orthoclase in which sodium may replace as much as 50 percent of the potassium: forms phenocrysts in some igneous rocks.

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sanidine British  

/ ˈsænɪˌdiːn, -dɪn /

noun

1. an alkali feldspar that is a high-temperature glassy form of orthoclase in flat, tabular crystals, found in lavas and dykes. Formula: KAlSi 3 O 8

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Other Word Forms

• sanidinic
  adjective

Etymology

Origin of sanidine

1805–15; < German Sanidin, equivalent to Greek sanid- (stem of sanís plank) + German -in -ine ²

Example Sentences

Renne, P. R., Mundil, R., Balco, G., Min, K. & Ludwig, K. R. Joint determination of 40K decay constants and 40Ar*/40K for the Fish Canyon sanidine standard, and improved accuracy for 40Ar/39Ar geochronology.

From Nature • Nov. 28, 2017

Matthews, N. E., Vazquez, J. A. & Calvert, A. T. Age of the Lava Creek supereruption and magma chamber assembly at Yellowstone based on 40Ar/39Ar and U-Pb dating of sanidine and zircon crystals.

From Textbooks • Jan. 1, 2017

Vesuvian lava, glass paste with numerous crystals of leucite; others of olivine, hornblende, and sanidine, porphyritically developed; small grains of magnetite.

From Volcanoes: Past and Present by Hull, Edward

To these succeeded during the Pliocene epoch still more highly silicated rocks of trachytic type, consisting of sanidine and oligoclase trachytes.

From Volcanoes: Past and Present by Hull, Edward

All the upper part of the mountain is composed of a pumiceous tufa, rich in sanidine and of a characteristic greenish colour.

From A Study of Recent Earthquakes by Davison, Charles