Afghanite Mineral Data

Afghanite Mineral Data +

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General Afghanite Information

Chemical Formula:

(Na,Ca,K)8(Si,Al)12O24(SO4,Cl,CO3)3·(H2O)

Composition:

Molecular Weight = 1,200.45 gm

Potassium 2.28 % K 2.75 % K₂O

Sodium 9.19 % Na 12.39 % Na₂O

Calcium 11.69 % Ca 16.35 % CaO

Aluminum 13.26 % Al 25.06 % Al₂O₃

Silicon 14.27 % Si 30.53 % SiO₂

Hydrogen 0.08 % H 0.75 % H₂O

Carbon 0.10 % C 0.37 % CO₂

Sulfur 3.39 % S 8.47 % SO₃

Chlorine 4.58 % Cl 4.58 % Cl

- % Cl -1.03 % -O=Cl₂

Oxygen 41.16 % O

______ ______

100.00 % 100.21 % = TOTAL OXIDE

Empirical Formula:

Na_4.8Ca_3.5K_0.7Si_6.1Al_5.9O₂₅(SO₄)_1.27Cl_1.55(CO₃)_0.1·0.5(H₂O)

Environment:

Generally associated with sodalite-group minerals.

IMA Status:

Approved IMA 1968

Locality:

Sar-e-Sang luzurite deposit in Afghanistan. Link to MinDat.org Location Data.

Name Origin:

From its locality.

Synonym:

ICSD 66847

PDF 46-1264

Afghanite Image

Images:

Afghanite

Comments: Parallel grouping of three, terminated, blue, opaque afghanite crystals set in matrix.
Location: Sar-eSang, Badakhshan, Afghanistan. Scale: Crystal size 3 cm.
© Dan Weinrich

Afghanite Crystallography

Axial Ratios:

a:c = 1:1.67188

Cell Dimensions:

a = 12.77, c = 21.35, Z = 4; V = 3,015.16 Den(Calc)= 2.64

Crystal System:

HexagonalSpace Group: P 6₃/mmc, P 6₃mc, or P 62c

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

By Intensity(I/I_o): 3.688(1), 3.298(1), 4.82(0.8),1.792(0.6), 2.13(0.6), 2.685(0.6), 3.997(0.6),

Crystal Structure:

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Ballirano P , Bonaccorsi E , Maras A , Merlino S , European Journal of Mineralogy , 9 (1997) p.21-30, Crystal structure of afghanite, the eight-layer member, of the cancrinite-group: evidence for long-range Si,Al ordering

Physical Properties of Afghanite

Cleavage:

[1010] Perfect

Color:

Blue, Colorless.

Density:

2.55 - 2.65, Average = 2.59

Diaphaniety:

Transparent

Fracture:

Conchoidal - Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).

Habit:

Massive - Uniformly indistinguishable crystals forming large masses.

Hardness:

5.5-6 - Knife Blade-Orthoclase

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Afghanite

Gladstone-Dale:

CI meas= 0.043 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= 0.058 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1992,KPDmeas= 0.2023,KC= 0.2114

Optical Data:

Uniaxial (+), w=1.523, e=1.529, bire=0.0060.

Calculated Properties of Afghanite

Electron Density:

r_electron=2.57 gm/cc
note: r_Afghanite=2.60 gm/cc.

Fermion Index

Fermion Index = 0.00728
Boson Index = 0.99272

Photoelectric:

PE_Afghanite= 3.25 barns/electron
U=PE_Afghanite x r_electron= 8.37 barns/cc.

Radioactivity:

GRapi = 32.54 (Gamma Ray American Petroleum Institute Units)

Estimated Radioactivity from Afghanite - barely detectable

Afghanite Classification

Dana Class:

76.2.5.1 (76)Tectosilicate Al-Si Framework

(76.2)Feldspathoids and related species

(76.2.5)Cancrinite group

76.2.5.1 Afghanite (Na,Ca,K)8(Si,Al)12O24(SO4,Cl,CO3)3·(H2O) P 6₃/mmc, P 6₃mc, or P 62c Hex

76.2.5.2 Bystrite (Na,K)7Ca(Si6Al6)O24S4.5·(H2O) P 3₁c 3m

76.2.5.3 Cancrinite Na6Ca2Al6Si6O24(CO3)2 P 6₃ 6

76.2.5.4 Cancrisilite Na7Al5Si7O24(C03)·3(H2O) P 6₃ 6

76.2.5.5 Davyne Na4K2Ca2Si6Al6O24(SO4)Cl2 P 6₃/m 6/m

76.2.5.6 Franzinite [(Na,K)30Ca10][Si30Al30O120](SO4)10·2(H2O) P 3₂1 3 2

76.2.5.7 Giuseppettite [Na42K16Ca6]S64Si48Al48O192(SO4)10Cl2·5H2O P 3₁c 3m

76.2.5.8 Hydroxycancrinite Na4(AlSiO4)3(OH)·(H2O) P 6₃ 6

76.2.5.9 Liottite (Ca,Na,K)8(Si,Al)12O24[(SO4),(CO3),Cl,OH]4·(H2O) P 6m2 6 m2

76.2.5.10 Microsommite (Na,Ca,K)7-8(Si,Al)12O24(Cl,SO4)2-3 P 6₃22 6 2 2

76.2.5.11 Pitiglianoite Na6K2Si6Al6O24(SO4)·2(H2O) P 6₃ 6

76.2.5.12 Quadridavyne (Na,K)6Ca2Al6Si6O24Cl4 P 6₃/m 6/m

76.2.5.13 Sacrofanite (Na,Ca,K)9Si6Al6O24[(OH),(SO4),(CO3),Cl)]4·n(H2O) P 6₃/mmc ? 6/m 2/m 2/m

76.2.5.14 Tounkite (Na,Ca,K)8Al6Si6O24(SO4)2Cl·(H2O) P 6₂22 6 2 2

76.2.5.15 Vishnevite (Na,Ca,K)6(Si,Al)12O24[(SO4),(CO3),Cl2]2-4·n(H2O) P 6₃22 6 2 2

76.2.5.16 Wenkite Ba4Ca6(Si,Al)20O39(OH)2(SO4)3·n(H2O)(?) P 62m 6 m2

76.2.5.17 Marinellite! [(Na,K)42Ca6](Si36Al36O144)(SO4)8Cl2·6(H2O) P 3₁c or P 2c Trig

76.2.5.18 IMA2004-043! (Na37K9Ca10)S56(Si42Al42)S84O168(SO4)12·6(H2O) P 6₃/m 6/m 2/m 2/m

Strunz Class:

VIII/J.09-50 VIII - Silicates

VIII/J - Tectosilicates (network) with anions unfamiliar to the tetraheders

VIII/J.09 - Cancrinite group

VIII/J.09-05 Hydroxycancrinite Na4(AlSiO4)3(OH)·(H2O) P 6₃ 6

VIII/J.09-10 Cancrinite Na6Ca2Al6Si6O24(CO3)2 P 6₃ 6

VIII/J.09-15 Cancrisilite Na7Al5Si7O24(C03)·3(H2O) P 6₃ 6

VIII/J.09-20 Davyne Na4K2Ca2Si6Al6O24(SO4)Cl2 P 6₃/m 6/m

VIII/J.09-25 Quadridavyne (Na,K)6Ca2Al6Si6O24Cl4 P 6₃/m 6/m

VIII/J.09-30 Microsommite (Na,Ca,K)7-8(Si,Al)12O24(Cl,SO4)2-3 P 6₃22 6 2 2

VIII/J.09-40 Giuseppettite [Na42K16Ca6]S64Si48Al48O192(SO4)10Cl2·5H2O P 3₁c 3m

VIII/J.09-45 Bystrite (Na,K)7Ca(Si6Al6)O24S4.5·(H2O) P 3₁c 3m

VIII/J.09-50 Afghanite (Na,Ca,K)8(Si,Al)12O24(SO4,Cl,CO3)3·(H2O) P 6₃/mmc, P 6₃mc, or P 62c Hex

VIII/J.09-55 Tounkite (Na,Ca,K)8Al6Si6O24(SO4)2Cl·(H2O) P 6₂22 6 2 2

VIII/J.09-60 Sacrofanite (Na,Ca,K)9Si6Al6O24[(OH),(SO4),(CO3),Cl)]4·n(H2O) P 6₃/mmc ? 6/m 2/m 2/m

VIII/J.09-65 Pitiglianoite Na6K2Si6Al6O24(SO4)·2(H2O) P 6₃ 6

VIII/J.09-70 Vishnevite (Na,Ca,K)6(Si,Al)12O24[(SO4),(CO3),Cl2]2-4·n(H2O) P 6₃22 6 2 2

VIII/J.09-80 Franzinite [(Na,K)30Ca10][Si30Al30O120](SO4)10·2(H2O) P 3₂1 3 2

VIII/J.09-90 Liottite (Ca,Na,K)8(Si,Al)12O24[(SO4),(CO3),Cl,OH]4·(H2O) P 6m2 6 m2

VIII/J.09-100 Wenkite Ba4Ca6(Si,Al)20O39(OH)2(SO4)3·n(H2O)(?) P 62m 6 m2

Other Afghanite Information

References:

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

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

Afghanite

(Na,Ca,K)8(Si,Al)12O24(SO4,Cl,CO3)3·(H2O)
Dana No: 76.2.5.1 Strunz No: VIII/J.09-50
Locality:

Notes: