Lennilenapeite
Lennilenapeite is an IMA-recognized mineral species in the silicate class, with the chemical formula K₇(Mg,Mn²⁺,Fe²⁺,Zn)₄₈(Si,Al)₇₂(O,OH)₂₁₆·16H₂O.
It is a member of the Stilpnomelane, Clay structural group.
Key properties: Mohs hardness 3; specific gravity 2.72; Brown streak; Vitreous to resinous luster; optically biaxial.
IMA symbol Lnl, IMA status: approved, named in 1982.
Apparently as both a primary and a late-stage low-temperature hydrothermal mineral in a metamorphosed stratiform zinc deposit.
It is found associated with Nelenite, tirodite, franklinite, willemite, sphalerite, dolomite.
The name refers to the Lenni Lenape Indians (original people in the Algonquin Indian language) who inhabited the Franklin area.
Index entry. This entry combines official IMA/RRUFF species data with published physical-property data — a full written entry hasn’t been published yet.
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