| Nelenite | |
| Category: | Phyllosilicate |
| Formula: | or |
| Imasymbol: | Nln[1] |
| Strunz: | 9.EE.15 |
| System: | Monoclinic |
| Class: | Prismatic (2/m) (same H-M symbol) |
| Symmetry: | C2/m |
| Unit Cell: | a = 23.24, b = 13.41 c = 7.38 [Å]; β = 105.21°; Z = 2 |
| Color: | Light to medium brown |
| Habit: | Coarsely granular to massive |
| Cleavage: | Perfect on |
| Mohs: | 5 |
| Luster: | Vitreous, resinous |
| Streak: | Light brown |
| Diaphaneity: | Transparent |
| Gravity: | 3.46 |
| Opticalprop: | Uniaxial (-) |
| Refractive: | 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 or [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]