nepheline
nounEtymology From Ancient Greek νεφέλη (nephélē, “cloud”), because crystals become cloudy when exposed to acid, + -ine.
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Chemistry, Geography, Geology, Mineralogy, Natural sciences, Physical sciences A feldspathoid mineral of silica-poor igneous, plutonic and volcanic rocks. Chemically, nepheline is a plagioclase feldspar with insufficient silica to satisfy the chemical bonds. Because of the unfilled bonds, nepheline weathers rapidly and can only be seen as inclusions in freshly broken rock.
- Synonyms
- nephelite
- Derived terms
- nepheline syenite, nephelinic, nephelinite