Cryolite Mineral Data

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."

Name Pronunciation:

Cryolite

Synonym:

ICSD 4029

PDF 23-772

Cryolite Image

Images:

Ralstonite Cryolite

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

Images:

Thomsenolite Cryolite

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:

Cryolithionite Cryolite

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:

Weberite Cryolite

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 - Prismatic H-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),

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

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Physical Properties of Cryolite

Cleavage:

None

Color:

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

Density:

2.95 - 3, Average = 2.97

Diaphaneity:

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:

Fluorescent, Short UV=bluish white.

Luster:

Vitreous - Greasy

Streak:

white

Optical Properties of Cryolite

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.

Calculated Properties of Cryolite

Electron Density:

Bulk Density (Electron Density)=2.82 gm/cc
note: Specific Gravity of Cryolite =2.96 gm/cc.

Fermion Index:

Fermion Index = 0
Boson Index = 1

Photoelectric:

PE_Cryolite= 1.16 barns/electron
U=PE_Cryolite x rElectron Density= 3.28 barns/cc.

Radioactivity:

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

Cryolite Classification

Dana Class:

11.06.01.01 (11)Halide Complexes; Alumino-fluorides

(11.06)with miscellaneous formulae

(11.06.01)Cryolite Group

11.06.01.01 Cryolite Na3AlF6 P 2₁/n 2/m

11.06.01.02 Simmonsite! Na2LiAlF6 P 2₁/n 2/m

Strunz Class:

03.CB.15 03 - HALIDES

03.C - Complex Halides

03.CB -Neso-aluminofluorides

03.CB.15 Cryolite Na3AlF6 P 2₁/n 2/m

03.CB.15 Elpasolite K2NaAlF6 F m3m 4/m 3 2/m

03.CB.15 Simmonsite! Na2LiAlF6 P 2₁/n 2/m

Other Cryolite Information

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 - 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 - WWW-MINCRYST

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

Cryolite

Na3AlF6
Dana No: 11.06.01.01 Strunz No: 03.CB.15
Locality:

Notes:

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