Nepheline
Species
Uncommon · Na₃K(Al₄Si₄O₁₆)
A feldspathoid of alkaline magmas, formed where there was too little silica for feldspar to crystallise. It never occurs beside quartz, which makes it a reliable marker of silica-poor rock.
Identity
- Formula
- Na₃K(Al₄Si₄O₁₆)
- Chemical class
- Silicate
- Also known as
- Eleolite
Crystallography
- Crystal system
- Hexagonal
- Habits
- Prismatic, Massive, Granular
- Fracture
- Subconchoidal
Physical properties
- Mohs hardness
- 6
- Density
- 2.59 g/cm³
- Luster
- Vitreous, Waxy
- Colors
- white, gray, brown, brownish gray, reddish white
- Streak
- white
- Transparency
- Transparent, Translucent, Opaque
Geology
- Origins
- Igneous, Volcanic
- Host rocks
- Granite, Volcanic rock
- Associated minerals
- Aegirine, Cancrinite, Sodalite, Hauyne
- Geography
- Norway, Russia, Canada
Classification
- Rarity
- Uncommon
- Gem quality
- No
Sources
- M. Pasero and others, IMA Commission on New Minerals, Nomenclature and Classification, The New IMA List of Minerals, updated September 2026. International Mineralogical Association (CNMNC), 2026.
- Nepheline. Mindat.org (Hudson Institute of Mineralogy).
- J. W. Anthony, R. A. Bideaux, K. W. Bladh, M. C. Nichols, Nepheline. Mineral Data Publishing, Handbook of Mineralogy, 2001.
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