Magnesioastrophyllite Mineral Data

General Magnesioastrophyllite Information

Chemical Formula:

K2Na[Na(Fe++,Fe+++,Mn)Mg2]Ti2Si8O26(OH)4F

Composition:

Molecular Weight = 1,275.02 gm

Potassium 6.13 % K 7.39 % K₂O

Sodium 3.61 % Na 4.86 % Na₂O

Magnesium 3.81 % Mg 6.32 % MgO

Titanium 7.51 % Ti 12.53 % TiO₂

Manganese 2.15 % Mn 3.10 % Mn₂O₃

Iron 19.71 % Fe 16.90 % FeO / 9.39 % Fe₂O₃

Silicon 17.62 % Si 37.70 % SiO₂

Hydrogen 0.32 % H 2.83 % H₂O

Oxygen 37.64 % O

Fluorine 1.49 % F 1.49 % F

- % F -0.63 % -O=F₂

______ ______

100.00 % 101.88 % = TOTAL OXIDE

Empirical Formula:

K₂Na₂Mg₂Fe³⁺_1.5Fe²⁺₃Mn³⁺_0.5Ti₂Si₈O₂₆(OH)₄F

Environment:

In a differentiated alkalic massif.

IMA Status:

Approved IMA 1963

Locality:

From Mts. Kukisvumchorr and Yukspor, Khibiny massif, Kola Peninsula, Russia. Link to MinDat.org Location Data.

Name Origin:

Named for the magnesium content and relationship to astrophyllite.

Synonym:

Magnesium astrophyllite - Renamed to Magnesioastrophyllite by Mineralogical Record, v39 (2008), p131

Magnesioastrophyllite Image

Images:

Magnesioastrophyllite

Comments: White chalky mass of magnesioastrophyllite in matrix.
Location: N'orkpakhk Mt., Khibiny Massif, Kola Peninsula, Russia. Scale: Specimen Size 35 x 25 x 10 mm.
© Sergey Vasiliev / Systematic Mineralogy

Magnesioastrophyllite Crystallography

Axial Ratios:

a:b:c =0.4534:1:0.2326

Cell Dimensions:

a = 10.43, b = 23, c = 5.35, Z = 2; beta = 102° V = 1,255.37 Den(Calc)= 3.37

Crystal System:

Monoclinic - Prismatic H-M Symbol (2/m) Space Group: A2/m

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

By Intensity(I/I_o): 3.38(1), 2.548(0.9), 10.1(0.8),

Physical Properties of Magnesioastrophyllite

Cleavage:

{100} Perfect, {010} Perfect

Color:

Brownish yellow, Green, Straw yellow.

Density:

3.32

Diaphaneity:

Translucent to Opaque

Hardness:

3 - Calcite

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Magnesioastrophyllite

Gladstone-Dale:

CI meas= 0.158 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= 0.17 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2033,KPDmeas= 0.2063,KC= 0.245
Ncalc = 1.81 - 1.83

Optical Data:

Biaxial (-), a=1.658, b=1.687, g=1.71, bire=0.0520, 2V(Calc)=82, 2V(Meas)=81.5-83.

Pleochroism (x):

bright yellow.

Pleochroism (y):

pale yellowish gray.

Pleochroism (z):

gray.

Calculated Properties of Magnesioastrophyllite

Electron Density:

Bulk Density (Electron Density)=3.24 gm/cc
note: Specific Gravity of Magnesioastrophyllite =3.32 gm/cc.

Fermion Index:

Fermion Index = 0.02
Boson Index = 0.98

Photoelectric:

PE_{Magnesioastrophyllite}= 9.10 barns/electron
U=PE_{Magnesioastrophyllite} x r_electron= 29.49 barns/cc.

Radioactivity:

GRapi = 86.39 (Gamma Ray American Petroleum Institute Units)
Concentration of Magnesioastrophyllite per GRapi unit = 1.16 (%)

Estimated Radioactivity from Magnesioastrophyllite - barely detectable

Magnesioastrophyllite Classification

Dana Class:

69.01.01.07 (69)Inosilicate Chains with Side Branches or Loops

(69.01)with (P=2, and N=4, 2 branches)

(69.01.01)Astrophyllite group

69.01.01.01 Astrophyllite K2Na(Fe,Mn)7Ti2Si8O26(OH)4 P1 1

69.01.01.02 Kupletskite K2Na(Mn,Fe)7(Ti,Nb)2Si8O26(OH)4F C 2/c 2/m

69.01.01.03 Kupletskite-(Cs) (Cs,K)2Na(Mn,Fe,Li)7(Ti,Nb)2Si8O26(OH)4F P1 1

69.01.01.04 Niobophyllite K2Na(Fe,Mn)7(Nb,Ti)2Si8O26(OH)4(F,O) P1,P 1 Tri

69.01.01.05 Zircophyllite K2(Na,Ca)(Mn,Fe)7(Zr,Nb)2Si8O26(OH)4F P1 1

69.01.01.06 Hydroastrophyllite (H3O,K)2Ca(Fe,Mn)5-6Ti2Si8O26(OH)4F P1 1

69.01.01.07 Magnesioastrophyllite K2Na[Na(Fe,Fe,Mn)Mg2]Ti2Si8O26(OH)4F A2/m 2/m

69.01.01.08 Niobokupletskite! K2Na(Mn,Zn,Fe)7(Nb,Zr,Ti)2Si8O26(OH)4(O,F) P1 1

69.01.01.09 Nalivkinite! Li2NaFe7Ti2Si8O24(OH)4F P1 1

Strunz Class:

09.DC.05 09 - SILICATES (Germanates)

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

09.DC -Inosilicates with branched 2-periodic single chains Si2O6 + 2SiO3 ï¿½ Si4O12

09.DC.05 Astrophyllite K2Na(Fe,Mn)7Ti2Si8O26(OH)4 P1 1

09.DC.05 Kupletskite-(Cs) (Cs,K)2Na(Mn,Fe,Li)7(Ti,Nb)2Si8O26(OH)4F P1 1

09.DC.05 Kupletskite K2Na(Mn,Fe)7(Ti,Nb)2Si8O26(OH)4F C 2/c 2/m

09.DC.05 Magnesioastrophyllite K2Na[Na(Fe,Fe,Mn)Mg2]Ti2Si8O26(OH)4F A2/m 2/m

09.DC.05 Hydroastrophyllite (H3O,K)2Ca(Fe,Mn)5-6Ti2Si8O26(OH)4F P1 1

09.DC.05 Niobophyllite K2Na(Fe,Mn)7(Nb,Ti)2Si8O26(OH)4(F,O) P1,P 1 Tri

09.DC.05 Nalivkinite! Li2NaFe7Ti2Si8O24(OH)4F P1 1

09.DC.05 Zircophyllite K2(Na,Ca)(Mn,Fe)7(Zr,Nb)2Si8O26(OH)4F P1 1

09.DC.05 Niobokupletskite! K2Na(Mn,Zn,Fe)7(Nb,Zr,Ti)2Si8O26(OH)4(O,F) P1 1

Other Magnesioastrophyllite Information

References:

NAME( AntBidBlaNic2) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(AntBidBlaNic2)

See Also:

Links to other databases for Magnesioastrophyllite :
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 Magnesioastrophyllite Specimen Label here :

Magnesioastrophyllite

K2Na[Na(Fe++,Fe+++,Mn)Mg2]Ti2Si8O26(OH)4F
Dana No: 69.01.01.07 Strunz No: 09.DC.05
Locality:

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