Manganoneptunite Mineral Data

General Manganoneptunite Information

Chemical Formula:

KNa2Li(Mn,Fe++)2Ti2Si8O24

Composition:

Molecular Weight = 906.78 gm

Potassium 4.31 % K 5.19 % K₂O

Sodium 5.07 % Na 6.84 % Na₂O

Lithium 0.77 % Li 1.65 % Li₂O

Titanium 10.56 % Ti 17.62 % TiO₂

Manganese 9.09 % Mn 11.73 % MnO

Iron 3.08 % Fe 3.96 % FeO

Silicon 24.78 % Si 53.01 % SiO₂

Oxygen 42.35 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

KNa₂LiMn²⁺_1.5Fe²⁺_0.5Ti₂Si₈O₂₄

Environment:

Found in syenites and syenite pegmatites.

IMA Status:

Valid Species (Pre-IMA) 1923

Locality:

Lovozero Massif, Kola Peninsula, Russia. Link to MinDat.org Location Data.

Name Origin:

Named for the composition and relationship to neptunite.

Synonym:

Mangan-neptunite - Renamed as Manganoneptunite by Mineralogical Record, v330 (2008), p131

Manganoneptunite Image

Images:

Manganoneptunite

Comments: Dark brown crystal of mangan-neptunite on matrix.
Location: Kibblehouse quarry, Perkiomenville, Pennsylvania, USA. Scale: Not Given.
© Lou Perloff / Photo Atlas of Minerals

Images:

Shkatulkalite Manganoneptunite

Comments: Pearly white shkatulkalite with brown mangan-neptunite grains.
Location: Shkatulka pegmatite, Umbozero mine, Alluaiv Mt, Lovozero Massif, Kola Peninsula, Murmanskaja Oblast', Northern Region, Russia. Scale: Picture size 4.5 mm.
© Thomas Witzke / Abraxas-Verlag

Manganoneptunite Crystallography

Axial Ratios:

a:b:c =1.3125:1:0.802

Cell Dimensions:

a = 16.38, b = 12.48, c = 10.01, Z = 4; beta = 115.4° V = 1,848.47 Den(Calc)= 3.26

Crystal System:

Monoclinic - Prismatic H-M Symbol (2/m) Space Group: C 2/m

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 1.506(1), 2.485(1), 1.483(0.9),

Physical Properties of Manganoneptunite

Color:

Red.

Density:

3.23

Diaphaneity:

Subopaque

Hardness:

5-6 - Between Apatite and Orthoclase

Luster:

Vitreous (Glassy)

Optical Properties of Manganoneptunite

Gladstone-Dale:

CI meas= 0.081 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= 0.089 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.217,KPDmeas= 0.219,KC= 0.2383
Ncalc = 1.77 - 1.78

Optical Data:

Biaxial (+), a=1.697, b=1.7, g=1.725, bire=0.0280, 2V(Calc)=40, 2V(Meas)=36.

Calculated Properties of Manganoneptunite

Electron Density:

Bulk Density (Electron Density)=3.15 gm/cc
note: Specific Gravity of Manganoneptunite =3.23 gm/cc.

Fermion Index:

Fermion Index = 0.02
Boson Index = 0.98

Photoelectric:

PE_{Manganoneptunite}= 6.43 barns/electron
U=PE_{Manganoneptunite} x r_electron= 20.26 barns/cc.

Radioactivity:

GRapi = 60.70 (Gamma Ray American Petroleum Institute Units)
Concentration of Manganoneptunite per GRapi unit = 1.65 (%)

Estimated Radioactivity from Manganoneptunite - barely detectable

Manganoneptunite Classification

Dana Class:

70.04.01.02 (70)Inosilicate Column or Tube Structures

(70.04)with linked chains forming cages

(70.04.01)Neptunite group

70.04.01.01 Neptunite KNa2Li(Fe,Mn)2Ti2Si8O24 Cc m

70.04.01.02 Manganoneptunite KNa2Li(Mn,Fe)2Ti2Si8O24 C 2/m 2/m

70.04.01.03 Watatsumiite! Na2KMn2LiV2Si8O24 Cc m

70.04.01.04 IMA2009-009 KNa2Li(Mg,Fe)2Ti2Si8O24 C 2/m 2/m

Strunz Class:

09.EH.05 09 - SILICATES (Germanates)

09.E - Phyllosilicates

09.EH -Transitional structures between phyllosilicate and other silicate units

09.EH.05 Neptunite KNa2Li(Fe,Mn)2Ti2Si8O24 Cc m

09.EH.05 Manganoneptunite KNa2Li(Mn,Fe)2Ti2Si8O24 C 2/m 2/m

09.EH.05 Watatsumiite! Na2KMn2LiV2Si8O24 Cc m

Other Manganoneptunite Information

References:

PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Manganoneptunite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - GeoScienceWorld
4 - Google Images
5 - Google Scholar
6 - MinDAT
7 - Mineralienatlas (Deutsch)
8 - Online Mineral Museum
9 - QUT Mineral Atlas
10 - Ruff.Info

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Print or Cut-and-Paste your Manganoneptunite Specimen Label here :

Manganoneptunite

KNa2Li(Mn,Fe++)2Ti2Si8O24
Dana No: 70.04.01.02 Strunz No: 09.EH.05
Locality:

Notes:

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