Arfvedsonite Mineral Data

General Arfvedsonite Information

Chemical Formula:

NaNa2(Fe++4Fe+++)Si8O22(OH)2

Composition:

Molecular Weight = 958.89 gm

Sodium 7.19 % Na 9.70 % Na₂O

Iron 29.12 % Fe 29.97 % FeO / 8.33 % Fe₂O₃

Silicon 23.43 % Si 50.13 % SiO₂

Hydrogen 0.21 % H 1.88 % H₂O

Oxygen 40.04 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Na₃Fe²⁺₄Fe³⁺(Si₈O₂₂)(OH)₂

Environment:

Igneous syenites and pegmatites.

IMA Status:

Valid Species (Pre-IMA) 1923

Locality:

Boulder Co., Colorado. Link to MinDat.org Location Data.

Name Origin:

Named after the Swedish chemist, J. A. Arfvedson (1792-1841).

Name Pronunciation:

Arfvedsonite + Pronunciation

Synonym:

ICSD 64820

PDF 42-1369

Arfvedsonite Image

Images:

Arfvedsonite

Comments: Prismatic crystals of black arfvedsonite in white feldspar matrix.
Location: Kangerdluarsuk, IlÃmaussaq Massif, Greenland. Scale: 8x3x3 cm.
© John Betts - Fine Minerals

Images:

Seidozerite Arfvedsonite

Comments: Dark red translucent seidozerite with vitreous, black arfvedsonite.
Location: Seidozero Lake, Lovozero Massif, Kola Peninsula, Murmansk District, Russia. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Arfvedsonite Crystallography

Axial Ratios:

a:b:c =0.5499:1:0.2944

Cell Dimensions:

a = 9.9, b = 18, c = 5.3, Z = 2; beta = 104° V = 916.41 Den(Calc)= 3.47

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): 3.161(1), 2.732(0.8), 8.51(0.7),

Physical Properties of Arfvedsonite

Cleavage:

{110} Perfect, {???} Imperfect

Color:

Black, Grayish green, Bluish gray.

Density:

3.44 - 3.45, Average = 3.44

Diaphaneity:

Translucent to opaque

Fracture:

Brittle - Generally displayed by glasses and most non-metallic minerals.

Habit:

Fibrous - Crystals made up of fibers.

Habit:

Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite)

Habit:

Stellate - Occurs as spherical, radial aggregates radiating from a "star" like point.

Hardness:

5.5-6 - Knife Blade-Orthoclase

Luminescence:

Non-fluorescent.

Luster:

Vitreous (Glassy)

Streak:

bluish gray

Optical Properties of Arfvedsonite

Gladstone-Dale:

CI meas= 0.065 (Fair) - where the CI = (1-KPDmeas/KC)
CI calc= 0.072 (Fair) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1964,KPDmeas= 0.1979,KC= 0.2117
Ncalc = 1.73

Optical Data:

Biaxial (-), a=1.652-1.699, b=1.66-1.705, g=1.666-1.708, bire=0.0090-0.0140, 2V(Calc)=70-80, 2V(Meas)=30-70. Dispersion r > v strong.

Pleochroism (x):

yellow, dark green, dark bluish green, or deep bluish green.

Pleochroism (y):

green, pale brown, dark bluish green, or bluish green.

Pleochroism (z):

bluish gray, black, brownish green, or dirty green.

Calculated Properties of Arfvedsonite

Electron Density:

Bulk Density (Electron Density)=3.37 gm/cc
note: Specific Gravity of Arfvedsonite =3.45 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Arfvedsonite= 9.68 barns/electron
U=PE_Arfvedsonite x rElectron Density= 32.63 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Arfvedsonite is Not Radioactive

Arfvedsonite Classification

Dana Class:

66.01.03c.09 (66)Inosilicate Double-Width Unbranched Chains, W=2

(66.01)with P=2 amphibole configuration

(66.01.03c)Group 4, the sodic amphiboles

66.01.03c.01 Glaucophane []Na2(Mg3Al2)Si8O22(OH)2 C 2/m 2/m

66.01.03c.02 Ferroglaucophane []Na2(Fe3Al2)Si8O22(OH)2 C 2/m 2/m

66.01.03c.03 Crossite? Na2(Mg,Fe)3(Al,Fe)2Si8O22(OH)2 C 2/m 2/m

66.01.03c.04 Magnesioriebeckite []Na2[(Mg,Fe)3Fe2]Si8O22(OH)2 C 2/m 2/m

66.01.03c.05 Riebeckite []Na2(Fe3Fe2)Si8O22(OH)2 C 2/m 2/m

66.01.03c.06 Eckermannite NaNa2(Mg4Al)Si8O22(OH)2 C 2/m 2/m

66.01.03c.07 Ferro-eckermannite NaNa2(Fe4Al)Si8O22(OH)2 C 2/m 2/m

66.01.03c.08 Magnesio-arfvedsonite NaNa2(Mg4Fe)Si8O22(OH)2 C 2/m 2/m

66.01.03c.09 Arfvedsonite NaNa2(Fe4Fe)Si8O22(OH)2 C 2/m 2/m

66.01.03c.09a Fluoro-magnesio-arfvedsonite! NaNa2(Mg,Fe)4Fe[Si8O22](F,OH)2 C 2/m 2/m

66.01.03c.09b Potassicarfvedsonite! KNa2Fe4FeSi8O22(OH)2 C 2/m 2/m

66.01.03c.10 Kozulite NaNa2Mn4(Fe,Al)Si8O22(OH)2 C 2/m 2/m

66.01.03c.11 Nyboite NaNa2(Mg3Al2)Si7AlO22(OH)2 C 2/m 2/m

66.01.03c.11a Ferronyboite! NaNa2(Fe)3Al2(Si7Al)O22(OH)2 C 2/m 2/m

66.01.03c.11b Ferric-ferronyboite! NaNa2(Fe)3(Fe)2(Si7Al)O22(OH)2 C 2/m 2/m

66.01.03c.11c Fluoronyboite! NaNa2(Al2Mg3)(Si7Al)O22(F,OH)2 C 2/m 2/m

66.01.03c.12 Leakeite NaNa2(Mg2Fe2Li)Si8O22(OH)2 C 2/m 2/m

66.01.03c.12a Ferroleakeite! NaNa2(Fe)3(Fe)2Li(Si8O22)(OH)2 C 2/m 2/m

66.01.03c.12b Potassicleakeite! KNa2Mg2Fe2LiSi8O22(OH)2 C 2/m 2/m

66.01.03c.13 Kornite Na(CaNa)Fe4(Al,Fe)Si7AlO22(OH)2 C 2/m 2/m

66.01.03c.14 Ungarettiite NaNa2(Mn2Mn3)Si8O22O2 C 2/m 2/m

66.01.03c.15 Fluoro-ferroleakeite NaNa2(Fe2Fe2Li)Si8O22F2 C 2/m 2/m

66.01.03c.16 Obertiite! NaNa2(Mg3FeTi)Si8O22(O,F,OH)2 C 2/m 2/m

66.01.03c.17 Dellaventuraite! NaNa2(Mg2,Mn,Li,Ti)Si8O22O2 C 2/m 2/m

Strunz Class:

09.DE.25 09 - SILICATES (Germanates)

09.D - Inosilicates* Structural terminology according to Liebau (1985)

09.DE -Inosilicates with 2-periodic double chains, Si4O11; amphibole family

09.DE.25 Arfvedsonite NaNa2(Fe4Fe)Si8O22(OH)2 C 2/m 2/m

09.DE.25 Ferroglaucophane []Na2(Fe3Al2)Si8O22(OH)2 C 2/m 2/m

09.DE.25 Crossite? Na2(Mg,Fe)3(Al,Fe)2Si8O22(OH)2 C 2/m 2/m

09.DE.25 Eckermannite NaNa2(Mg4Al)Si8O22(OH)2 C 2/m 2/m

09.DE.25 Glaucophane []Na2(Mg3Al2)Si8O22(OH)2 C 2/m 2/m

09.DE.25 Fluoro-ferroleakeite NaNa2(Fe2Fe2Li)Si8O22F2 C 2/m 2/m

09.DE.25 Ferro-eckermannite NaNa2(Fe4Al)Si8O22(OH)2 C 2/m 2/m

09.DE.25 Ferroleakeite! NaNa2(Fe)3(Fe)2Li(Si8O22)(OH)2 C 2/m 2/m

09.DE.25 Ferronyboite! NaNa2(Fe)3Al2(Si7Al)O22(OH)2 C 2/m 2/m

09.DE.25 Ferric-ferronyboite! NaNa2(Fe)3(Fe)2(Si7Al)O22(OH)2 C 2/m 2/m

09.DE.25 Obertiite! NaNa2(Mg3FeTi)Si8O22(O,F,OH)2 C 2/m 2/m

09.DE.25 Nyboite NaNa2(Mg3Al2)Si7AlO22(OH)2 C 2/m 2/m

09.DE.25 Magnesioriebeckite []Na2[(Mg,Fe)3Fe2]Si8O22(OH)2 C 2/m 2/m

09.DE.25 Kozulite NaNa2Mn4(Fe,Al)Si8O22(OH)2 C 2/m 2/m

09.DE.25 Kornite Na(CaNa)Fe4(Al,Fe)Si7AlO22(OH)2 C 2/m 2/m

09.DE.25 Leakeite NaNa2(Mg2Fe2Li)Si8O22(OH)2 C 2/m 2/m

09.DE.25 Magnesio-arfvedsonite NaNa2(Mg4Fe)Si8O22(OH)2 C 2/m 2/m

09.DE.25 Ungarettiite NaNa2(Mn2Mn3)Si8O22O2 C 2/m 2/m

09.DE.25 Riebeckite []Na2(Fe3Fe2)Si8O22(OH)2 C 2/m 2/m

09.DE.25 Potassicleakeite! KNa2Mg2Fe2LiSi8O22(OH)2 C 2/m 2/m

09.DE.25 Fluoronyboite! NaNa2(Al2Mg3)(Si7Al)O22(F,OH)2 C 2/m 2/m

09.DE.25 Fluoro-magnesio-arfvedsonite! NaNa2(Mg,Fe)4Fe[Si8O22](F,OH)2 C 2/m 2/m

09.DE.25 Potassicarfvedsonite! KNa2Fe4FeSi8O22(OH)2 C 2/m 2/m

09.DE.25 Dellaventuraite! NaNa2(Mg2,Mn,Li,Ti)Si8O22O2 C 2/m 2/m

Other Arfvedsonite Information

References:

NAME( Duda&Rejl90) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Heinrich65)

See Also:

Links to other databases for Arfvedsonite :
1 - Alkali-Nuts(English)
2 - Alkali-Nuts(Francais)
3 - Am. Min. Crystal Structure Database
4 - Amethyst Galleries' Mineral Gallery
5 - Athena
6 - EUROmin Project
7 - Ecole des Mines de Paris
8 - GeoScienceWorld
9 - Google Images
10 - Google Scholar
11 - Handbook of Mineralogy (MinSocAm)
12 - Handbook of Mineralogy (UofA)
13 - MinDAT
14 - Mineralienatlas (Deutsch)
15 - Online Mineral Museum
16 - QUT Mineral Atlas
17 - Ruff.Info
18 - UCLA - Petrography Thin-Sections
19 - WWW-MINCRYST

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

Arfvedsonite

NaNa2(Fe++4Fe+++)Si8O22(OH)2
Dana No: 66.01.03c.09 Strunz No: 09.DE.25
Locality:

Notes:

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