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Neptunite Mineral Data

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General Neptunite Information

Help on Chemical  Formula: Chemical Formula: KNa2Li(Fe++,Mn)2Ti2Si8O24
Help on Composition: Composition: Molecular Weight = 907.69 gm
   Potassium   4.31 %  K     5.19 % K2O
   Sodium      5.07 %  Na    6.83 % Na2O
   Lithium     0.76 %  Li    1.65 % Li2O
   Titanium   10.55 %  Ti   17.60 % TiO2
   Manganese   3.03 %  Mn    3.91 % MnO
   Iron        9.23 %  Fe   11.87 % FeO
   Silicon    24.75 %  Si   52.96 % SiO2
   Oxygen     42.30 %  O
             ______        ______ 
             100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: KNa2LiFe2+1.5Mn2+0.5Ti2Si8O24
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1893
Help on Locality: Locality: Benitoite mine, San Benito, Co., California, USA. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Neptune, the Roman god of the sea, because it was found with aegirine, named for the Scandinavian god of the sea.
Help on Name Pronunciation: Name Pronunciation: Neptunite + Pronunciation Say NEPTUNITE
Help on Synonym: Synonym: Carlosite
  ICSD 71360
  PDF 43-677
 

Neptunite Image

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  Neptunite   Natrolite

Comments: Jet-black square prisms of neptunite etched out of the enclosing white natrolite with minor benitoite.
Location: Benitoite Gem Mine. San Benito Co. California, USA. Scale: 6.5 x 6 cm.
© Fabre Minerals

Neptunite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =1.3167:1:0.8008
Help on Cell Dimensions: Cell Dimensions: a = 16.46, b = 12.5, c = 10.01, Z = 4; beta = 115.4° V = 1,860.47 Den(Calc)= 3.24
Help on Crystal System: Crystal System: Monoclinic - Domatic H-M Symbol (m) Space Group: Cc
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 3.186(1), 9.6(0.6), 3.517(0.45),
Help on Forms: Forms:

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Help on Above

Forms: ( 0 0 1) ( 1 0 0) ( 0 1 0) ( 1 1 1) ( 1 1 0)

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Physical Properties of Neptunite

Help on Cleavage: Cleavage: {110} Good
Help on Color: Color: Black, Red.
Help on Density: Density: 3.23
Help on Diaphaneity: Diaphaneity: Translucent
Help on Fracture: Fracture: Conchoidal - Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).
Help on Habit: Habit: Crystalline - Coarse - Occurs as well-formed coarse sized crystals.
Help on Habit: Habit: Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).
Help on Habit: Habit: Tabular - Form dimensions are thin in one direction.
Help on Hardness: Hardness: 5-6 - Between Apatite and Orthoclase
Help on Luminescence: Luminescence: Non-fluorescent.
Help on Luster: Luster: Vitreous (Glassy)
Help on Streak: Streak: brown
 

Optical Properties of Neptunite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.081 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= 0.084 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2175,KPDmeas= 0.2182,KC= 0.2375
Ncalc = 1.77
Help on Optical Data: Optical Data: Biaxial (+), a=1.69-1.6908, b=1.6927-1.7, g=1.7194-1.736, bire=0.0294-0.0452, 2V(Calc)=36-56, 2V(Meas)=36-49. Dispersion r < v strong.
Help on Pleochroism (x): Pleochroism (x): yellow orange.
Help on Pleochroism (y): Pleochroism (y): orange.
Help on Pleochroism (z): Pleochroism (z): deep red.
 

Calculated Properties of Neptunite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=3.16 gm/cc
note: Specific Gravity of Neptunite =3.23 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.02
Boson Index = 0.98
Help on Photoelectric: Photoelectric: PENeptunite = 6.71 barns/electron
U=PENeptunite x relectron= 21.19 barns/cc.
Help on Radioactivity: Radioactivity:

GRapi = 60.73 (Gamma Ray American Petroleum Institute Units)
Concentration of Neptunite per GRapi unit = 1.65 (%)

Estimated Radioactivity from Neptunite - barely detectable

 

Neptunite Classification

Help on  Dana Class: Dana Class: 70.04.01.01 (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
Help on  Strunz Class: 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 Neptunite Information

Help on References: References: NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Dana8)
Help on See Also: See Also: Links to other databases for Neptunite :
1 - Alkali-Nuts(English)
2 - Alkali-Nuts(Francais)
3 - Am. Min. Crystal Structure Database
4 - Amethyst Galleries' Mineral Gallery
5 - Athena
6 - CalTech Mineral Spectroscopy
7 - EUROmin Project
8 - Ecole des Mines de Paris
9 - GeoScienceWorld
10 - Glendale Community College
11 - Google Images
12 - Google Scholar
13 - Handbook of Mineralogy (MinSocAm)
14 - Handbook of Mineralogy (UofA)
15 - HyperPhysics
16 - MinDAT
17 - Mineralienatlas (Deutsch)
18 - Online Mineral Museum
19 - QUT Mineral Atlas
20 - Ruff.Info
21 - WWW-MINCRYST
22 - theimage

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

Neptunite

KNa2Li(Fe++,Mn)2Ti2Si8O24
Dana No: 70.04.01.01 Strunz No: 09.EH.05
Locality:

 

Notes:

 

 
   
 


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