oligoclase

American  

[ol-i-goh-kleys] / ˈɒl ɪ goʊˌkleɪs /

noun

Mineralogy.

1. a kind of plagioclase feldspar occurring commonly in white crystals, sometimes shaded with gray, green, or red.

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oligoclase British  

/ ˈɒlɪɡəʊˌkleɪs /

noun

1. a white, bluish, or reddish-yellow feldspar mineral of the plagioclase series, consisting of aluminium silicates of sodium and calcium. Formula: NaAlSi 3 O 8 .CaAl 2 Si 2 O 8

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oligoclase Scientific  

/ ŏl′ĭ-gō-klās′,ō′lĭ- /

1. A white to gray triclinic mineral of the plagioclase feldspar group. Oligoclase occurs in igneous rocks with a relatively high silica content, such as granite. Chemical formula: (Na,Ca)(Al,Si)AlSi ₂ O ₈ .

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Etymology

Origin of oligoclase

First recorded in 1825–35; oligo- + -clase

Example Sentences

See Examples For:

oligoclase

Felspar if present may be orthoclase and oligoclase.

From Encyclopaedia Britannica, 11th Edition, Volume 12, Slice 5 "Greek Law" to "Ground-Squirrel" by Various

Of their minerals felspar Is usually the most abundant, and is principally labradorite and bytownite, though anorthite occurs in some, while oligoclase and orthoclase have been found in others.

From Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 4 "G" to "Gaskell, Elizabeth" by Various

Felspars, 103; albite, 103; composition of, 103; labradorite, 220; oligoclase, 103, 214, 220; orthoclase, 103, 214, 220; phosphoric acid in, 211; potash manures, 213; potash in, percentage of, 213, 220.

From Manures and the principles of manuring by Aikman, Charles Morton

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

The accessory minerals of these rocks are principally oligoclase, muscovite, apatite and zircon.

From Encyclopaedia Britannica, 11th Edition, Volume 2, Slice 2 "Anjar" to "Apollo" by Various