Cryolite Mineral Data

Cryolite Mineral Data +

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General Cryolite Information

Chemical Formula:

Na3AlF6

Composition:

Molecular Weight = 209.94 gm

Sodium 32.85 % Na 44.28 % Na₂O

Aluminum 12.85 % Al 24.28 % Al₂O₃

Fluorine 54.30 % F 54.30 % F

- % F -22.86 % -O=F₂

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Na₃AlF₆

Environment:

Large bed in a granitic vein in gray gneiss.

IMA Status:

Valid Species (Pre-IMA) 1799

Locality:

Ivigtut and Arksukfiord, West Greenland. Link to MinDat.org Location Data.

Name Origin:

Named from the Greek, kryos "frost" and lithos "stone."

Synonym:

ICSD 4029

PDF 23-772

Cryolite Image

Images:

Cryolite Ralstonite

Comments: Massive cryolite with solution cavities lined with octahedral ralstonite crystals.
Location: Ivigtut, Greenland. Scale: Picture size 0.5 cm.
© John Veevaert

Images:

Cryolite Thomsenolite

Comments: Massive, white cryolite with solution cavities lined with prismatic Thomsenolite crystals.
Location: Ivigtut, Greenland. Scale: .
© John Veevaert

Images:

Cryolite

Comments: Massive cryolite with one section of lustrous crystal faces.
Location: Ivigtut, Greenland. Scale: Picture size 4 cm.
© John Veevaert

Images:

Cryolite Cryolithionite

Comments: White translucent crystalline cryolithionite in brown cryolite.
Location: Ivigtut, Greenland. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Images:

Cryolite

Comments: Red-brown crystalline massive cryolite.
Location: Katugin River, Siberia, Russia. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Images:

Cryolite Weberite

Comments: Gray weberite masses in white cryolite.
Location: Ivigtut, Greenland. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Cryolite Crystallography

Axial Ratios:

a:b:c =0.9642:1:1.3892

Cell Dimensions:

a = 5.4, b = 5.6, c = 7.78, Z = 2; beta = 90.183° V = 235.27 Den(Calc)= 2.96

Crystal System:

Monoclinic - PrismaticH-M Symbol (2/m) Space Group: P 2₁/n

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

By Intensity(I/I_o): 1.941(1), 2.747(0.95), 3.883(0.6),

Forms:

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Forms: [ 1 0 1] [ 1 1 0] [ 1 1 0] [ 0 1 1] [ 0 0 1]

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Crystal Structure:

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Hawthorne F C , Ferguson R B , The Canadian Mineralogist , 13 (1975) p.377-382, Refinement of the crystal structure of cryolite

View Additional jPOWD Structure files for Cryolite
[1] [10] [11] [12] [2] [3] [4] [5] [6] [7] [8] [9]

Physical Properties of Cryolite

Cleavage:

None

Color:

Brownish black, Colorless, Gray, White, Reddish brown.

Density:

2.95 - 3, Average = 2.97

Diaphaniety:

Transparent to translucent

Fracture:

Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern.

Habit:

Euhedral Crystals - Occurs as well-formed crystals showing good external form.

Habit:

Massive - Granular - Common texture observed in granite and other igneous rock.

Hardness:

2.5-3 - Finger Nail-Calcite

Luminescence:

None.

Luster:

Vitreous - Greasy

Streak:

white

Optical Properties of Cryolite

Gladstone-Dale:

CI meas= 0.287 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= 0.284 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1146,KPDmeas= 0.114,KC= 0.1599

Optical Data:

Biaxial (+), a=1.3385-1.339, b=1.3389-1.339, g=1.3396-1.34, bire=0.0010-0.0011, 2V(Calc)=0-76, 2V(Meas)=43. Dispersion none.

Pleochroism (x):

colorless.

Pleochroism (y):

colorless.

Pleochroism (z):

colorless.

Calculated Properties of Cryolite

Electron Density:

r_electron=2.82 gm/cc
note: r_Cryolite=2.96 gm/cc.

Fermion Index

Fermion Index = 0
Boson Index = 1

Photoelectric:

PE_Cryolite= 1.16 barns/electron
U=PE_Cryolite x r_electron= 3.28 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)

Cryolite is Not Radioactive

Cryolite Classification

Dana Class:

11.6.1.1 (11)Halide Complexes; Alumino-fluorides

(11.6)with miscellaneous formulae

(11.6.1)Dana Group

11.6.1.1 Cryolite Na3AlF6 P 2₁/n 2/m

11.6.1.2 Simmonsite! Na2LiAlF6 P 2₁/n 2/m

Strunz Class:

III/B.03-30 III - Halogenides

III/B - Double halogenides without water, with [BF4]1-,[SiF6]2- and [AlF6]3-

III/B.03 - Kryolithionite - Calcjarlite series

III/B.03-10 Cryolithionite Na3Li3Al2F12 I a3d 4/m 3 2/m

III/B.03-20 Colquiriite CaLiAlF6 P 3c 3 2/m

III/B.03-25 Simmonsite! Na2LiAlF6 P 2₁/n 2/m

III/B.03-30 Cryolite Na3AlF6 P 2₁/n 2/m

III/B.03-40 Elpasolite K2NaAlF6 F m3m 4/m 3 2/m

III/B.03-45 Bogvadite Na2SrBa2Al4F20 Pnmn,Pn2n Ortho

III/B.03-48 Jorgensenite! Na2(Sr,Ba)14Na2Al12F64(OH,F) C 2/m 2/m

III/B.03-50 Jarlite Na(Sr,Na,[])7(Mg,[])Al6F32(OH,H2O)2 C 2/m 2/m

III/B.03-60 Calcjarlite Na(Ca,Sr)3Al3(F,OH)16 C 2/m 2/m

Other Cryolite Information

References:

NAME( Ford32) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Mason68)

See Also:

Links to other databases for Cryolite :
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 - Google Images
9 - Google Scholar
10 - Handbook of Mineralogy (MinSocAm)
11 - Handbook of Mineralogy (UofA)
12 - MinDAT
13 - MinMax(Deutsch)
14 - MinMax(English)
15 - Mineralienatlas (Deutsch)
16 - QUT Mineral Atlas
17 - Ruff.Info
18 - WWW-MINCRYST

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

Cryolite

Na3AlF6
Dana No: 11.6.1.1 Strunz No: III/B.03-30
Locality:

Notes: