Feldspathoid mineral that forms instead of feldspar in silica-undersaturated igneous rocks. Important rock-forming mineral. Color: White, gray, yellowish, greenish. Luster: Vitreous to greasy. Streak: White. Cleavage: Poor. Hardness: 5.5-6. Transparency: Translucent to opaque. Crystal system: Hexagonal. Chemical formula: Na,K AlSiO₄. Specific gravity: 2.55-2.66. Formation: Crystallizes from silica-undersaturated alkaline magmas where there is insufficient silica to form feldspar. Common geological settings: Russia Kola Peninsula , Norway, Canada, Brazil; found in nepheline syenites and phonolites. Common look-alikes and related entries: Feldspar, Quartz, Leucite.
These authoritative resources support category-level nomenclature, terminology, identification methods, and safety. When a specimen-specific safety warning appears, the public-health source listed here directly supports that precaution. They are not line-by-line citations for every other property on this entry, and natural specimens vary.
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GeoMiner
Last updated
2026-03-30T14:37:49.576707+00:00
Review status
Published; not independently peer-reviewed
IMA–CNMNC List of Mineral Names — International Mineralogical Association. Official mineral-name, nomenclature, and classification records.
Mineral ID Key — Mineralogical Society of America. Physical-property identification methods, repeat-testing guidance, and limitations.
Feldspathoid mineral that forms instead of feldspar in silica-undersaturated igneous rocks. Important rock-forming mineral.
How can you identify Nepheline?
Compare several properties rather than relying on colour alone. This entry records colour: White, gray, yellowish, greenish; lustre: Vitreous to greasy; streak: White; Mohs hardness: 5.5-6; cleavage: Poor; crystal system: Hexagonal; transparency: Translucent to opaque. Confirm an important identification with additional field tests or qualified laboratory work.
How does Nepheline form?
Crystallizes from silica-undersaturated alkaline magmas where there is insufficient silica to form feldspar.
Where is Nepheline commonly found?
Russia Kola Peninsula , Norway, Canada, Brazil; found in nepheline syenites and phonolites.
What is Nepheline commonly confused with?
Nepheline may be confused with Feldspar, Quartz, Leucite. Compare multiple diagnostic properties because colour and surface appearance can overlap.
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