Nelenite
Appearance
Nelenite | |
---|---|
![]() Nelenite (brown) andfranklinite(metallic, black), from Franklin, Franklin Mining District, Sussex County, New Jersey, US | |
General | |
Category | Phyllosilicate |
Formula (repeating unit) | (Mn,Fe)16As3Si12O36(OH)17or (Mn,Fe)16(Si12O30)(OH)14[As3+3O6(OH)3] |
IMA symbol | Nln[1] |
Strunz classification | 9.EE.15 |
Crystal system | Monoclinic |
Crystal class | Prismatic (2/m) (sameH-M symbol) |
Space group | C2/m |
Unit cell | a = 23.24, b = 13.41 c = 7.38 [Å]; β = 105.21°; Z = 2 |
Identification | |
Color | Light to medium brown |
Crystal habit | Coarsely granular to massive |
Cleavage | Perfect on {0001} |
Mohs scalehardness | 5 |
Luster | Vitreous, resinous |
Streak | Light brown |
Diaphaneity | Transparent |
Specific gravity | 3.46 |
Optical properties | Uniaxial (-) |
Refractive index | nω= 1.718 nε= 1.700 |
Birefringence | δ = 0.018 |
Pleochroism | Visible ε = colorless and ω = light brown |
References | [2][3][4] |
Neleniteis a raremanganeseironphyllosilicatearsenatemineral found inFranklin Furnace,New Jersey.
Its chemical formula is(Mn,Fe)16As3Si12O36(OH)17or(Mn,Fe)16(Si12O30)(OH)14[As3+3O6(OH)3][2]
Discovery and occurrence
[edit]It was first describe in 1984 for an occurrence in the Trotter Mine, Franklin Mining District,Sussex County, New Jersey.It was named for Joseph A. Nelen of the Smithsonian Institution.[2][4]It has also been reported fromMontgomery County, Virginiaand theSuceavadistrict ofRomania.[2]At thetype localityin New Jersey it occurs associated withactinolite,calcite,willemite,tirodite,rhodonite,apatite,lennilenapeite, stilpnomelane,microclineandtalc.[4]
References
[edit]- ^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.S2CID235729616.
- ^abcdMindat.org - Nelenite
- ^Webmineral - Nelenite
- ^abcHandbook of Mineralogy - Nelenite