Back نيفيلين Arabic Nefelin Azerbaijani Нефелін Byelorussian Нефелин Bulgarian Nefelina Catalan Nefelín Czech Nephelin German Νεφελίνης Greek Nefelino Esperanto Nefelina Spanish
| Nepheline | |
|---|---|
 | |
| General | |
| Category | Tectosilicate, feldspathoid |
| Formula (repeating unit) | (Na,K)AlSiO4 |
| IMA symbol | Nph[1] |
| Strunz classification | 9.FA.05 |
| Crystal system | Hexagonal |
| Crystal class | Pyramidal (6) H–M symbol: (6) |
| Space group | P63 |
| Identification | |
| Formula mass | 146.08 g/mol |
| Color | White, gray, brown, brownish gray, or reddish white |
| Crystal habit | Massive granular to prismatic |
| Twinning | On [1010], [3365], and [1122] |
| Cleavage | [1010] Poor |
| Fracture | Subconchoidal |
| Mohs scale hardness | 6 |
| Luster | Vitreous to greasy |
| Streak | White |
| Specific gravity | 2.55–2.65 (average: 2.59) |
| Optical properties | Uniaxial (−) |
| Refractive index | nω = 1.529–1.546 nε = 1.526–1.542 |
| Birefringence | δ = 0.003–0.004 |
| Other characteristics | non-radioactive, non-magnetic, non-fluorescent |
| References | [2][3][4] |
Nepheline, also called nephelite (from Ancient Greek νεφέλη (nephélē) 'cloud'), is a rock-forming mineral in the feldspathoid group – a silica-undersaturated aluminosilicate, Na3KAl4Si4O16, that occurs in intrusive and volcanic rocks with low silica, and in their associated pegmatites. It is used in glass and ceramic manufacturing and other industries, and has been investigated as an ore of aluminium.
- ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
- ^ Anthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W.; Nichols, Monte C. (2005). "Nepheline" (PDF). Handbook of Mineralogy. Mineral Data Publishing. Retrieved 13 August 2022.
- ^ "Nepheline". Mindat.org.
- ^ Barthelmy, David (2014). "Nepheline Mineral Data". Webmineral.com. Retrieved 13 August 2022.