feldspathoid

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Related to feldspathoidal: alkali feldspar, sanidine

feld·spath·oid

 (fĕld-spăth′oid′, fĕl-)
n.
Any of a group of relatively rare minerals that are chemically very similar to feldspars, but have too little silica to qualify as feldspars.

[feldspath (obsolete variant of feldspar, from obsolete German Feldspath, feldspar; see feldspar) + -oid.]

feldspathoid

(ˈfɛldspəˌθɔɪd) or

felspathoid

n
(Geological Science) any of a group of rock-forming minerals, such as leucite and sodalite, that are similar to feldspars but contain less silica

feld•spath•oid

(ˈfɛld spæˌθɔɪd, ˈfɛl-)

adj.
1. Also, feld`spath•oi′dal. of or pertaining to a group of minerals similar in chemical composition to certain feldspars except for a lower silica content.
n.
2. a mineral of this group, as nepheline or leucite.
[1895–1900; < German Feldspat(h) (see feldspar) + -oid]
References in periodicals archive ?
Most of the rocks in the study area include syenites, feldspathoidal syenites, fenites, carbonates and associated rocks(Siddique, 1965, 1967).
These rocks contain mineral 'nepheline' as their major component along with other feldspathoidal minerals, like, cancrinite and sodalite [1, 12, 13, 17].
The absence of a modern petrological study of the host rock of zeolites also motivated the origin of the herein presented study on petrography, rock-forming minerals and geochemistry of the host rock of anomalous feldspathoidal trachyandesite composition in the Ceske stfedohofi Mts.
Geology and petrology of the feldspathoidal syenites and pegmatites of the Koga area, Chamla valley, Swat, West Pakistan.
Alkali-rich rocks and feldspathoidal rocks are tare (feldspathoids and quartz are mutually exclusive) and plagioclase typically dominates over alkalifeldspar.