Cryolite Mineral Data
General Cryolite Information
Chemical Formula:
Na3AlF6
Composition:
Molecular Weight = 209.94 gm
Sodium 32.85 % Na 44.28 % Na2 O
Aluminum 12.85 % Al 24.28 % Al2 O3
Fluorine 54.30 % F 54.30 % F
- %
F -22.86 % -O=F2
______ ______
100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:
Na3 AlF6
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:
Images:
Images:
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
X Ray Diffraction:
By Intensity(I/Io ): 1.941(1), 2.747(0.95), 3.883(0.6),
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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:
PECryolite = 1.16 barns/electronU=PECryolite x r Electron 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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