Weberite
A valid IMA mineral species - grandfathered
This page is currently not sponsored. Click here to sponsor this page.
About Weberite
Theobald Weber
Formula:
Na2Mg[AlF6]F
Colour:
Grayish white; colourless in transmitted light.
Lustre:
Vitreous
Hardness:
3½
Specific Gravity:
2.96
Crystal System:
Orthorhombic
Name:
Named after Theobald Christian Fridrich Weber (13 September 1823, Copenhagen, Denmark - 3 September 1886, Svendborg, Denmark), a founder of the Danish cryolite industry in 1857.
This page provides mineralogical data about Weberite.
Unique Identifiers
Mindat ID:
4253
Long-form identifier:
mindat:1:1:4253:2
Similar Names
| Webnerite | A synonym of 'Andorite' |
IMA Classification of Weberite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
Na2MgAlF7
First published:
1938
Classification of Weberite
3.CB.25
3 : HALIDES
C : Complex halides
B : Neso-aluminofluorides
3 : HALIDES
C : Complex halides
B : Neso-aluminofluorides
11.6.13.1
11 : HALIDE COMPLEXES
6 : Aluminofluorides - Isolated Octahedra
11 : HALIDE COMPLEXES
6 : Aluminofluorides - Isolated Octahedra
8.6.8
8 : Halides - Fluorides, Chlorides, Bromides and Iodides; also Fluoborates and Fluosilicates
6 : Halides of Al
8 : Halides - Fluorides, Chlorides, Bromides and Iodides; also Fluoborates and Fluosilicates
6 : Halides of Al
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Web | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Physical Properties of Weberite
Vitreous
Transparency:
Translucent
Colour:
Grayish white; colourless in transmitted light.
Streak:
White
Hardness:
3½ on Mohs scale
Cleavage:
Poor/Indistinct
On {101} poor; on {010} indistinct.
On {101} poor; on {010} indistinct.
Fracture:
Irregular/Uneven
Density:
2.96 g/cm3 (Measured) 2.966 g/cm3 (Calculated)
Optical Data of Weberite
Type:
Biaxial (+)
RI values:
nα = 1.344 - 1.346 nβ = 1.346 - 1.348 nγ = 1.347 - 1.350
2V:
Measured: 83° (3), Calculated: 88°
Max. Birefringence:
δ = 0.003 - 0.004
Based on recorded range of RI values above.
Based on recorded range of RI values above.
Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
Surface Relief:
Very High (negative)
Relative to Canada balsam mounting medium (n ≈ 1.537).
Relative to Canada balsam mounting medium (n ≈ 1.537).
This shows the grain boundary and Becke line effect under plane-polarised
light, based on the contrast between this mineral's average refractive
index and the mounting medium. It does not take into account mineral
colouration.
In focus
Interference Figure:
This shows the idealized biaxial acute bisectrix (Bxa) interference figure
- the conoscopic view for a grain cut perpendicular to the acute bisectrix, using
this mineral's 2V. The two small white dots mark the melatopes - the points
where the two optic axes emerge - and are shown only when they fall within the
field of view. The coloured bands are isochromatics, and the dark bands are
isogyres.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Dispersion:
none
Chemistry of Weberite
Mindat Formula:
Na2Mg[AlF6]F
Element Weights:
Elements listed:
Crystallography of Weberite
Crystal System:
Orthorhombic
Class (H-M):
mmm(2/m2/m2/m) - Dipyramidal
Space Group:
Immm
Cell Parameters:
a = 7.31 Å, b = 7.06 Å, c = 9.99 Å
Ratio:
a:b:c = 1.035 : 1 : 1.415
Unit Cell V:
515.57 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Irregular grains and masses. Inclusions in cryolite.
Twinning:
With [111] as twin axis and {011} as composition plane, commonly as contact twins.
Crystal Structure
Load
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Show
Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
Remove metal-metal sticks
Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
Remove metal-metal sticks
Display Options
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
View
CIF File Best | x | y | z | a | b | c
CIF File Best | x | y | z | a | b | c
Rotation
Stop | Start
Stop | Start
Labels
Console Off | On | Grey | Yellow
Console Off | On | Grey | Yellow
Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure
| ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
|---|---|---|---|---|---|---|---|
| 0013483 | Weberite | Knop O, Cameron T S, Jochem K (1982) What is the true space group of weberite? Journal of Solid State Chemistry 43 213-221 | 1982 | Ivigtut, Greenland | 0 | 293 | |
| 0013481 | Weberite | Knop O, Cameron T S, Jochem K (1982) What is the true space group of weberite? Journal of Solid State Chemistry 43 213-221 | 1982 | Ivigtut, Greenland | 0 | 293 | |
| 0013479 | Weberite | Knop O, Cameron T S, Jochem K (1982) What is the true space group of weberite? Journal of Solid State Chemistry 43 213-221 | 1982 | Ivigtut, Greenland | 0 | 293 | |
| 0013477 | Weberite | Knop O, Cameron T S, Jochem K (1982) What is the true space group of weberite? Journal of Solid State Chemistry 43 213-221 | 1982 | Ivigtut, Greenland | 0 | 293 | |
| 0015669 | Weberite | Giuseppetti G, Tadini C (1978) Re-examination of the crystal structure of weberite Tschermaks Mineralogische und Petrographische Mitteilungen 25 57-62 | 1978 | Ivigtut, Greenland | 0 | 293 | |
| 0013484 | Weberite | Knop O, Cameron T S, Jochem K (1982) What is the true space group of weberite? Journal of Solid State Chemistry 43 213-221 | 1982 | Ivigtut, Greenland | 0 | 133 | |
| 0013482 | Weberite | Knop O, Cameron T S, Jochem K (1982) What is the true space group of weberite? Journal of Solid State Chemistry 43 213-221 | 1982 | Ivigtut, Greenland | 0 | 133 | |
| 0013480 | Weberite | Knop O, Cameron T S, Jochem K (1982) What is the true space group of weberite? Journal of Solid State Chemistry 43 213-221 | 1982 | Ivigtut, Greenland | 0 | 133 | |
| 0013478 | Weberite | Knop O, Cameron T S, Jochem K (1982) What is the true space group of weberite? Journal of Solid State Chemistry 43 213-221 | 1982 | Ivigtut, Greenland | 0 | 133 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 1.779 Å | (100) |
| 2.95 Å | (90) |
| 2.89 Å | (90) |
| 5.05 Å | (60) |
| 5.89 Å | (50) |
| 2.30 Å | (50) |
| 1.542 Å | (50) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Near-surface Processes | |
| 23 : Subaerial aqueous alteration by non-redox-sensitive fluids (see also #47) | |
| Stage 4b: Highly evolved igneous rocks | >3.0 |
| 35 : Ultra-alkali and agpaitic igneous rocks | |
| 36 : Carbonatites, kimberlites, and related igneous rocks |
Type Occurrence of Weberite
General Appearance of Type Material:
Irregular grains, to 2.5 mm, in fluorite or cryolite.
Place of Conservation of Type Material:
University of Copenhagen, Copenhagen, Denmark, 1981.936
Geological Setting of Type Material:
Cryolite deposit and overlying pegmatite.
Associated Minerals at Type Locality:
Other Language Names for Weberite
Common Associates
Associations Based on Photo Data:
| 9 photos of Weberite associated with Fluorite | CaF2 |
| 7 photos of Weberite associated with Quartz | SiO2 |
| 7 photos of Weberite associated with Cryolite | Na2NaAlF6 |
| 6 photos of Weberite associated with Gearksutite | Ca[Al(F,OH)5(H2O)] |
| 6 photos of Weberite associated with Jørgensenite | Na2(Sr,Ba)14Na2Al12F64(OH,F)4 |
| 6 photos of Weberite associated with 'Sericite' | KAl2(AlSi3O10)(OH)2 |
| 6 photos of Weberite associated with Muscovite | KAl2(AlSi3O10)(OH)2 |
| 5 photos of Weberite associated with Topaz | Al2(SiO4)(F,OH)2 |
| 5 photos of Weberite associated with Baryte | BaSO4 |
| 4 photos of Weberite associated with Pyrite | FeS2 |
Related Minerals - Strunz-mindat Grouping
| 3.CB.05 | Cryolithionite | Na3Al2(LiF4)3 |
| 3.CB.15 | Elpasolite | K2NaAlF6 |
| 3.CB.15 | Simmonsite | Na2LiAlF6 |
| 3.CB.15 | Cryolite | Na2NaAlF6 |
| 3.CB.20 | Colquiriite | CaLi[AlF6] |
| 3.CB.25 | Leonardsenite | MgAlF5 · 2H2O |
| 3.CB.30 | Karasugite | SrCa[Al(F,OH)7] |
| 3.CB.35 | Usovite | Ba2CaMgAl2F14 |
| 3.CB.40 | Thomsenolite | NaCa[AlF6] · H2O |
| 3.CB.40 | Pachnolite | NaCa[AlF6] · H2O |
| 3.CB.45 | Carlhintzeite | Ca2[AlF6]F · H2O |
| 3.CB.50 | Yaroslavite | Ca3Al2F10(OH)2 · H2O |
| 3.CB.55 | Sbacchiite | Ca2AlF7 |
| 3.CB.60 | Verneite | Na2Ca3Al2F14 |
Other Information
Notes:
Slightly soluble in water. Readily soluble in an AlCl3 solution.
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Internet Links for Weberite
mindat.org URL:
https://www.mindat.org/min-4253.html
Please feel free to link to this page.
Please feel free to link to this page.
Search Engines:
External Links:
Mineral Dealers:
References for Weberite
Reference List:
Ferguson, R.B. (1948) Observations on weberite and jarlite. American Mineralogist: 33(3-4): 195-195.
Ferguson, R. B. (1949) Observations on some aluminium fluoride minerals. American Mineralogist, 34 (5-6) 383-397
Localities for Weberite
Showing 13 localities.
symbol to view information about a locality.
The Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
ⓘ - Click for references and further information on this occurrence.
? - Indicates mineral may be doubtful at this locality.
- Good crystals or important locality for species.
- World class for species or very significant.
(TL) - Type Locality for a valid mineral species.
(FRL) - First Recorded Locality for everything else (eg varieties).
All localities listed without proper references should be considered as questionable.
Antarctica | |
| Viramonte et al. (1974) |
Australia | |
| |
| Bottrill +1 other reference |
Finland | |
| Ilkka Mikkola collection +1 other reference |
Greenland (TL) | |
| Meddelelser om Grønland (1938) +2 other references |
Kazakhstan | |
| Bailey (1980) |
Russia | |
| Starikova et al. (2015) +1 other reference |
Ukraine | |
| Liventseva (n.d.) +2 other references |
USA | |
| Eckel et al. (1997) |
| Eckel et al. (1997) |
| Gross et al. (1966) +1 other reference | |
| Armbrustmacher (1988) +1 other reference |
| Mandarino (2000) |
Quick NavTopAbout WeberiteUnique IdentifiersSimilar NamesIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography Crystal StructureX-Ray Powder DiffractionGeological EnvironmentType Occurrence Other LanguagesCommon AssociatesStrunz-MindatOther InformationInternet Links References Localities Locality List
Ivigtut Mine, Ivigtut stock, Arsuk Fjord, Sermersooq, Greenland