Feldspathoid - definition of feldspathoid by The Free Dictionary
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feld·spath·oid (fĕld-spăth′oid′, fĕl-)
Any of a group of relatively rare minerals that are chemically very similar to feldspars, but have too little silica to qualify as feldspars.
(obsolete variant of feldspar
, from obsolete German Feldspath
; see feldspar
) + -oid
feldspathoid (ˈfɛldspəˌθɔɪd) or
(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-)
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.
References in periodicals archive
In its thin sections, the rock has a hypo-crystalline matrix which is composed of porphyritic texture and is rich in a sprinkled opaque mineral, plagioclase, feldspathoid
mineral and obsidian.
2] alkaline intrusive complex comprising a carbonatite core that is surrounded by nepheline syenite, feldspathoid
syenite and other mafic intrusive phases.
It is a partially decomposed granite feldspathoid
having a greater diversity of alkaloids causing it to go into a gradual melt with less surface tension than true feldspars.