| Nelenite | |
|---|---|
Nelenite (brown) and franklinite (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) (same H-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 scale hardness | 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] |
Nelenite is a rare manganese iron phyllosilicate arsenate mineral found in Franklin Furnace, New Jersey.
Its chemical formula is (Mn,Fe)16As3Si12O36(OH)17or(Mn,Fe)16(Si12O30)(OH)14[As3+3O6(OH)3][2]
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 from Montgomery County, Virginia and the Suceava district of Romania.[2] At the type locality in New Jersey it occurs associated with actinolite, calcite, willemite, tirodite, rhodonite, apatite, lennilenapeite, stilpnomelane, microcline and talc.[4]
 | This article about a specific silicate mineral is a stub. You can help Wikipedia by expanding it. |
