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About LennilenapeiteHide

K6-7(Mg,Mn,Fe,Zn)48(Si,Al)72(O,OH)216 · 16H2O
Very dark in hand sample, chips are dark brown or light green
Specific Gravity:
Crystal System:
Named in 1984 by Pete J. Dunn, Donald R. Peacor, and William B. Simmons for the Lenni Lenape indigenous tribe which inhabited the area around Franklin, N.J., USA. The words "Lenni Lenape" mean "the original people" in the Algonquin language of the time.
Isostructural with:
This page provides mineralogical data about Lennilenapeite.

Classification of LennilenapeiteHide

First Published:

9 : SILICATES (Germanates)
E : Phyllosilicates
G : Double nets with 6-membered and larger rings

74 : PHYLLOSILICATES Modulated Layers
1 : Modulated Layers with joined islands

16 : Silicates Containing Aluminum and other Metals
20 : Aluminosilicates of Fe, Mg and alkalis

Physical Properties of LennilenapeiteHide

Very dark in hand sample, chips are dark brown or light green
Perfect {001} and imperfect nearly perpendicular to (001)
2.72 g/cm3 (Measured)    
Measured using heavy-liquid technique

Optical Data of LennilenapeiteHide

Biaxial (-)
RI values:
nα = 1.553(2) nβ = 1.594(4) nγ = 1.594(4)
Max Birefringence:
δ = 0.041
Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
Surface Relief:
X faint brown to colorless, Y = Z dark brown (type material)
X pale yellow-brown, Y = Z dark olive brown (cotype material)

Chemical Properties of LennilenapeiteHide

K6-7(Mg,Mn,Fe,Zn)48(Si,Al)72(O,OH)216 · 16H2O
IMA Formula:
K7(Mg,Mn2+,Fe2+,Zn)48(Si,Al)72(O,OH)216 · 16H2O
Common Impurities:

Crystallography of LennilenapeiteHide

Crystal System:
Cell Parameters:
a = 21.91 Å
Unit Cell V:
0.00 ų (Calculated from Unit Cell)

Type Occurrence of LennilenapeiteHide

General Appearance of Type Material:
Black, lustrous, in small flattened aggregates that range up to 1 cm across.
Place of Conservation of Type Material:
Holotype and cotype lennilenapeite are in the mineral collection at Harvard University, under catalog numbers H105542 and H108573, respectively.
Dunn, P.J., Peacor, D.R., Simmons, W.B. (1984) Lennilenapeite, the Mg-analogue of stilpnomelane, and chemical data on other stilpnomelane species from Franklin, New Jersey. The Canadian Mineralogist: 22: 259-263.

Synonyms of LennilenapeiteHide

Other Language Names for LennilenapeiteHide

Relationship of Lennilenapeite to other SpeciesHide

Other Members of this group:
Franklinphilite(K,Na)4(Mn2+,Mg,Zn)48(Si,Al)72(O,OH)216 · 6H2OTric.
Parsettensite(K,Na,Ca)7.5(Mn,Mg)49Si72O168(OH)50 · nH2OMon. 2/m : B2/m
Stilpnomelane(K,Ca,Na)(Fe2+,Mg,Al)8(Si,Al)12(O,OH)36 · nH2OTric. 1 : P1

Common AssociatesHide

Associated Minerals Based on Photo Data:
Sphalerite10 photos of Lennilenapeite associated with Sphalerite on
Calcite9 photos of Lennilenapeite associated with Calcite on
Quartz2 photos of Lennilenapeite associated with Quartz on
Hematite1 photo of Lennilenapeite associated with Hematite on

Related Minerals - Nickel-Strunz GroupingHide

9.EG.05CymriteBaAl2Si2(O,OH)8 · H2OMon.
9.EG.10Naujakasite(Na,K)6(Fe2+,Mn2+,Ca)(Al,Fe)4Si8O26Mon. 2/m : B2/m
9.EG.15DmisteinbergiteCa(Al2Si2O8)Hex. 6/mmm (6/m 2/m 2/m) : P6/mmm
9.EG.20KampfiteBa12(Si11Al5)O31(CO3)8Cl5Mon. m
9.EG.25SträtlingiteCa2Al2SiO7 · 8H2OTrig.
9.EG.25VertumniteCa4Al4Si4O6(OH)24 · 3H2OMon. 2/m : P21/m
9.EG.30Eggletonite(Na,K,Ca)2(Mn,Fe)8(Si,Al)12O29(OH)7 · 11H2OMon.
9.EG.30Ganophyllite(K,Na,Ca)2Mn8(Si,Al)12(O,OH)32 · 8H2OMon.
9.EG.30Tamaite(Ca,K,Ba,Na)3-4Mn24(Si,Al)40(O,OH)112 · 21H2OMon.
9.EG.35ZussmaniteK(Fe,Mg,Mn)13(Si,Al)18O42(OH)14Trig. 3 : R3
9.EG.40Franklinphilite(K,Na)4(Mn2+,Mg,Zn)48(Si,Al)72(O,OH)216 · 6H2OTric.
9.EG.40Parsettensite(K,Na,Ca)7.5(Mn,Mg)49Si72O168(OH)50 · nH2OMon. 2/m : B2/m
9.EG.40Stilpnomelane(K,Ca,Na)(Fe2+,Mg,Al)8(Si,Al)12(O,OH)36 · nH2OTric. 1 : P1
9.EG.45Tuscanite(K(Ca,Na)6(Si,Al)10O22[SO4,CO3,(OH)2] · H2OMon.
9.EG.55WickenburgiteCaPb3Al2Si10O24(OH)6Trig. 3m : P3 1c
9.EG.60HyttsjöitePb18Ba2Ca5Mn2+2Fe3+2Si30O90Cl · 6H2OTrig.
9.EG.65ArmbrusteriteK5Na7Mn15[(Si9O22)4](OH)10 · 4H2OMon. 2/m : B2/m
9.EG.70Britvinite[Pb7(OH)3F(BO3)2(CO3)][Mg4.5(OH)3(Si5O14)]Tric. 1 : P1
9.EG.75Bannisterite(Ca,K,Na)(Mn2+,Fe2+)10(Si,Al)16O38(OH)8 · nH2OMon. 2/m : B2/b

Related Minerals - Dana Grouping (8th Ed.)Hide,Ca,Na)(Fe2+,Mg,Al)8(Si,Al)12(O,OH)36 · nH2OTric. 1 : P1,Na)4(Mn2+,Mg,Zn)48(Si,Al)72(O,OH)216 · 6H2OTric.,K,Na)(Mn2+,Fe2+)10(Si,Al)16O38(OH)8 · nH2OMon. 2/m : B2/b

Related Minerals - Hey's Chemical Index of Minerals GroupingHide

16.20.3Sodium Gedrite{Na}{Mg2}{Mg3Al2}(Al3Si5O22)(OH)2
16.20.6Wonesite(Na,K)(Mg,Fe,Al)6((Al,Si)4O10)2(OH,F)4Mon. 2/m : B2/m
16.20.9Stilpnomelane(K,Ca,Na)(Fe2+,Mg,Al)8(Si,Al)12(O,OH)36 · nH2OTric. 1 : P1
16.20.10Glauconite(K,Na)(Mg,Fe2+,Fe3+)(Fe3+,Al)(Si,Al)4O10(OH)2Mon. 2/m : B2/m

Fluorescence of LennilenapeiteHide

No discernible fluorescence in ultraviolet radiation

Other InformationHide

Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

References for LennilenapeiteHide

Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
Dunn, P.J., Peacor, D.R., Simmons, W.B. (1984) Lennilenapeite, the Mg-analogue of stilpnomelane, and chemical data on other stilpnomelane species from Franklin, New Jersey. The Canadian Mineralogist: 22: 259-263.
Dunn, P.J., Chao, G.Y., Fleischer, M., Ferraiolo, J.A., Langley, R.H., Pabst, A., Zilczer, J.A. (1985) New mineral names. American Mineralogist: 70: 214-221.

Internet Links for LennilenapeiteHide

Localities for LennilenapeiteHide

This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.

Locality ListHide

- This locality has map coordinates listed. - This locality has estimated coordinates. ⓘ - Click for further information on this occurrence. ? - Indicates mineral may be doubtful at this locality. - Good crystals or important locality for species. - World class for species or very significant. (TL) - Type Locality for a valid mineral species. (FRL) - First Recorded Locality for everything else (eg varieties). Struck out - Mineral was erroneously reported from this locality. Faded * - Never found at this locality but inferred to have existed at some point in the past (eg from pseudomorphs.)

All localities listed without proper references should be considered as questionable.
  • Honshu Island
    • Chubu Region
      • Gifu Prefecture
Endo, S. (2008) Chigaku Kenkyu, 57, 3-10.
  • Suceava Co.
    • Suceava district
      • Iacobeni (Jakobeny; Jacobeny; Jakabfalva)
  • California
    • Mendocino Co.
      • Coastal Range
        • Longvale
          • North of Longvale
Gunnar Färber
  • New Jersey
    • Sussex Co.
      • Franklin mining district
        • Franklin
Dunn, P.J., et al: Canadian Mineralogist:22:259-263; Dunn(1995):Pt4:474-475.
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