Vránaite
A valid IMA mineral species
This page is currently not sponsored. Click here to sponsor this page.
About Vránaite
Stanislav Vrána
Formula:
Al16B4Si4O38
The empirical formula is close to Li1.08Be0.47Fe0.02Al14.65B3.89Si3.88O36.62
Colour:
Colorless
Lustre:
Vitreous
Hardness:
4½
Specific Gravity:
2.99 (Calculated)
Crystal System:
Monoclinic
Name:
Named in honor of Stanislav Vrána (1936-2018), petrologist with the Czech Geological Survey. Among other things, he studied the petrology and mineralogy of borosilicate minerals. He was also editor-in-chief of the Journal of the Czech Geological Society.
Related to boralsilite and boromullite.
Product of breakdown of spodumene.
Crystal structure details: chains of AlO6 octahedra, || [010], cross linked by disilicate groups; triangular BO3 groups; chains with AlO4 and two AlO5 polyhedra; partially occupied BO4 polyhedron.
Product of breakdown of spodumene.
Crystal structure details: chains of AlO6 octahedra, || [010], cross linked by disilicate groups; triangular BO3 groups; chains with AlO4 and two AlO5 polyhedra; partially occupied BO4 polyhedron.
Name Encoding
ASCII-7:
Vranaite
Unique Identifiers
Mindat ID:
46967
Long-form identifier:
mindat:1:1:46967:0
Similar Names
| Verneite | A valid IMA mineral species | Na2Ca3Al2F14 |
| Veronite | A synonym of Celadonite |
IMA Classification of Vránaite
Approved
Approval year:
2015
First published:
2016
Type description reference:
Cempírek, Jan, Grew, Edward S., Kampf, Anthony R., Ma, Chi, Novák, Milan, Gadas, Petr, Škoda, Radek, Vašinová-Galiová, Michaela, Pezzotta, Federico, Groat, Lee A., Krivovichev, Sergey V. (2016) Vránaite, ideally Al16B4Si4O38, a new mineral related to boralsilite, Al16B6Si2O37, from the Manjaka pegmatite, Sahatany Valley, Madagascar. American Mineralogist, 101 (9) 2108-2117 doi:10.2138/am-2016-5686
Classification of Vránaite
9.BD.40
9 : SILICATES (Germanates)
B : Sorosilicates
D : Si2O7 groups, with additional anions; cations in tetrahedral [4] and greater coordination
9 : SILICATES (Germanates)
B : Sorosilicates
D : Si2O7 groups, with additional anions; cations in tetrahedral [4] and greater coordination
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 |
|---|---|---|
| Vrá | 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 Vránaite
Vitreous
Transparency:
Transparent
Colour:
Colorless
Streak:
White
Hardness:
4½ on Mohs scale
Tenacity:
Brittle
Cleavage:
None Observed
Parting:
None observed
Fracture:
Irregular/Uneven
Density:
2.99 g/cm3 (Calculated)
Optical Data of Vránaite
Type:
Biaxial (-)
RI values:
nα = 1.607(1) nβ = 1.634(1) nγ = 1.637(1)
2V:
Calculated: 36.4°
Max. Birefringence:
δ = 0.030
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.
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.
Surface Relief:
Moderate
Dispersion:
None observed
Pleochroism:
Non-pleochroic
Comments:
X≈c; Y≈a; Z=b
Chemistry of Vránaite
Mindat Formula:
Al16B4Si4O38
The empirical formula is close to Li1.08Be0.47Fe0.02Al14.65B3.89Si3.88O36.62
The empirical formula is close to Li1.08Be0.47Fe0.02Al14.65B3.89Si3.88O36.62
Element Weights:
Elements listed:
Crystallography of Vránaite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
B2/m
Setting:
C2/m
Cell Parameters:
a = 10.3832(1) Å, b = 5.6682(7) Å, c = 10.823(1) Å
β = 90.11(1)°
β = 90.11(1)°
Ratio:
a:b:c = 1.832 : 1 : 1.909
Unit Cell V:
636.98 ų (Calculated from Unit Cell)
Comment:
previously reported space group setting is I2/m
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 5.40 Å | (96) |
| 5.19 Å | (99) |
| 4.97 Å | (74) |
| 3.658 Å | (75) |
| 3.403 Å | (100) |
| 2.496 Å | (61) |
| 2.171 Å | (75) |
| 1.518 Å | (61) |
Locality:
Reference:
Cempírek, Jan, Grew, Edward S., Kampf, Anthony R., Ma, Chi, Novák, Milan, Gadas, Petr, Škoda, Radek, Vašinová-Galiová, Michaela, Pezzotta, Federico, Groat, Lee A., Krivovichev, Sergey V. (2016) Vránaite, ideally Al16B4Si4O38, a new mineral related to boralsilite, Al16B6Si2O37, from the Manjaka pegmatite, Sahatany Valley, Madagascar. American Mineralogist, 101 (9) 2108-2117 doi:10.2138/am-2016-5686
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Near-surface Processes | |
| 22 : Hydration and low-? subsurface aqueous alteration (see also #23) | |
| Stage 4b: Highly evolved igneous rocks | >3.0 |
| 34 : Complex granite pegmatites |
Type Occurrence of Vránaite
General Appearance of Type Material:
subparallel prisms, up to 100 μm long, intergrown
Place of Conservation of Type Material:
In the mineralogical collections of the Natural History Museum of Los Angeles County, California, USA, catalogue number 65609, and the Department of Mineralogy and Petrography, Moravian Museum,Brno, Czech Republic catalogue numbers B11277 and B11278
Geological Setting of Type Material:
elbaite-subtype pegmatite
Associated Minerals at Type Locality:
Reference:
Cempírek, Jan, Grew, Edward S., Kampf, Anthony R., Ma, Chi, Novák, Milan, Gadas, Petr, Škoda, Radek, Vašinová-Galiová, Michaela, Pezzotta, Federico, Groat, Lee A., Krivovichev, Sergey V. (2016) Vránaite, ideally Al16B4Si4O38, a new mineral related to boralsilite, Al16B6Si2O37, from the Manjaka pegmatite, Sahatany Valley, Madagascar. American Mineralogist, 101 (9) 2108-2117 doi:10.2138/am-2016-5686
Synonyms of Vránaite
Other Language Names for Vránaite
Common Associates
Associations Based on Photo Data:
Related Minerals - Strunz-mindat Grouping
| 9.BD.05 | Bertrandite | Be4(Si2O7)(OH)2 |
| 9.BD.10 | Hemimorphite | Zn4Si2O7(OH)2 · H2O |
| 9.BD.15 | Junitoite | CaZn2Si2O7 · H2O |
| 9.BD.20 | Tinzenite | Ca2Mn2+4Al4[B2Si8O30](OH)2 |
| 9.BD.20 | Axinite-(Fe) | Ca2Fe2+Al2BSi4O15OH |
| 9.BD.20 | Dubińskaite | Ca4Sc2Al4[Be2Si8O30](OH)2 |
| 9.BD.20 | Axinite-(Mg) | Ca2MgAl2BSi4O15OH |
| 9.BD.20 | Axinite-(Mn) | Ca2Mn2+Al2BSi4O15(OH) |
| 9.BD.25 | Vistepite | SnMn4B2Si4O16(OH)2 |
| 9.BD.30 | Boralsilite | Al16B6O30(Si2O7) |
| 9.BD.35 | Werdingite | (Mg,Fe)2Al14Si4B4O37 |
Other Information
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 Vránaite
mindat.org URL:
https://www.mindat.org/min-46967.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 Vránaite
Reference List:
www.nhm.org (2012) http://www.nhm.org/site/research-collections/mineral-sciences/research-studies/anthony-r-kampf
Hålenius, U., Hatert, F., Pasero, M., Mills, S. J. (2016) New minerals and nomenclature modifications approved in 2015 and 2016, CNMNC Newsletter No 29. Mineralogical Magazine, 80 (1) 199-205 doi:10.1180/minmag.2016.080.080
Cempírek, Jan, Grew, Edward S., Kampf, Anthony R., Ma, Chi, Novák, Milan, Gadas, Petr, Škoda, Radek, Vašinová-Galiová, Michaela, Pezzotta, Federico, Groat, Lee A., Krivovichev, Sergey V. (2016) Vránaite, ideally Al16B4Si4O38, a new mineral related to boralsilite, Al16B6Si2O37, from the Manjaka pegmatite, Sahatany Valley, Madagascar. American Mineralogist, 101 (9) 2108-2117 doi:10.2138/am-2016-5686
Localities for Vránaite
Showing 1 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.
Madagascar (TL) | |
| Hålenius et al. (2016) +1 other reference |
Quick NavTopAbout VránaiteName EncodingUnique IdentifiersSimilar NamesIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography X-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesCommon AssociatesStrunz-MindatOther InformationInternet Links References Localities Locality List
Manjaka, Sahatany Valley, Ibity, Antsirabe II District, Vakinankaratra, Madagascar