Sekaninaite
A valid IMA mineral species
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About Sekaninaite
Formula:
(Fe,Mg)2Al3(AlSi5O18)
Colour:
grayish-blue to bluish-violet
Lustre:
Vitreous
Hardness:
7 - 7½
Specific Gravity:
2.76 - 2.77
Crystal System:
Orthorhombic
Name:
Named in honour of Josef Sekanina (4 September 1901, Knínice u Boskovic, Czech Republic - 28 November 1986, Letovice, Czech Republic), Czech mineralogist who first found the mineral.
Type Locality:
Dimorph of:
Unique Identifiers
Mindat ID:
3609
Long-form identifier:
mindat:1:1:3609:8
IMA Classification of Sekaninaite
Approved
IMA Formula:
Fe2+2Al4Si5O18
First published:
1975
Classification of Sekaninaite
9.CJ.10
9 : SILICATES (Germanates)
C : Cyclosilicates
J : [Si6O18]12- 6-membered single rings (sechser-Einfachringe), without insular complex anions
9 : SILICATES (Germanates)
C : Cyclosilicates
J : [Si6O18]12- 6-membered single rings (sechser-Einfachringe), without insular complex anions
61.2.1.2
61 : CYCLOSILICATES Six-Membered Rings
2 : Six-Membered Rings with Al substituted rings
61 : CYCLOSILICATES Six-Membered Rings
2 : Six-Membered Rings with Al substituted rings
16.19.3
16 : Silicates Containing Aluminum and other Metals
19 : Aluminosilicates of Fe and Mg
16 : Silicates Containing Aluminum and other Metals
19 : Aluminosilicates of Fe and Mg
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
Symbol | Source | Reference |
---|---|---|
Skn | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Skn | The Canadian Mineralogist (2019) | The Canadian Mineralogist (2019) The Canadian Mineralogist list of symbols for rock- and ore-forming minerals (December 30, 2019). download |
Physical Properties of Sekaninaite
Vitreous
Transparency:
Transparent, Translucent
Colour:
Grayish-blue to bluish-violet
Hardness:
7 - 7½ on Mohs scale
Cleavage:
Imperfect/Fair
{100} imperfect
{100} imperfect
Parting:
{001}
Density:
2.76 - 2.77 g/cm3 (Measured) 2.78 g/cm3 (Calculated)
Optical Data of Sekaninaite
Type:
Biaxial (-)
RI values:
nα = 1.561 nβ = 1.572 nγ = 1.576
2V:
Measured: 66° , Calculated: 60°
Max. Birefringence:
δ = 0.015
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:
weak
Pleochroism:
Visible
Comments:
X = colorless; Y = blue; Z = pale blue.
Chemistry of Sekaninaite
Mindat Formula:
(Fe,Mg)2Al3(AlSi5O18)
Element Weights:
Common Impurities:
Ti,Mn,Ca,Na,K,H2O
Crystallography of Sekaninaite
Crystal System:
Orthorhombic
Class (H-M):
mmm (2/m 2/m 2/m) - Dipyramidal
Space Group:
Cccm
Setting:
Cccm
Cell Parameters:
a = 17.230(5) Å, b = 9.835(3) Å, c = 9.314(3) Å
Ratio:
a:b:c = 1.752 : 1 : 0.947
Unit Cell V:
1,578.32 ų (Calculated from Unit Cell)
Z:
4
Morphology:
poorly developed crystals, to 70 cm.
Twinning:
Type material - usually twinned on {110} and {310}, simulating hexagonal symmetry.
Crystal Structure
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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) |
---|---|---|---|---|---|---|---|
0000709 | Sekaninaite | Hochella M F, Brown G E, Ross F K, Gibbs G V (1979) High-temperature crystal chemistry of hydrous Mg- and Fe-cordierite American Mineralogist 64 337-351 | ![]() | 1979 | 0 | 297 | |
0000710 | Sekaninaite | Hochella M F, Brown G E, Ross F K, Gibbs G V (1979) High-temperature crystal chemistry of hydrous Mg- and Fe-cordierite American Mineralogist 64 337-351 | ![]() | 1979 | 0 | 648 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
d-spacing | Intensity |
---|---|
8.583 Å | (100) |
3.386 Å | (100) |
3.376 Å | (100) |
4.081 Å | (83) |
3.076 Å | (74) |
3.143 Å | (64) |
3.043 Å | (57) |
Geological Environment
Paragenetic Mode(s):
Paragenetic Mode | Earliest Age (Ga) |
---|---|
Stage 4b: Highly evolved igneous rocks | >3.0 |
34 : Complex granite pegmatites | |
Stage 5: Initiation of plate tectonics | <3.5-2.5 |
41 : Mantle metasomatism |
Type Occurrence of Sekaninaite
Place of Conservation of Type Material:
Moravian Museum, Brno, Czech Republic, A6108.
Associated Minerals at Type Locality:
Synonyms of Sekaninaite
Other Language Names for Sekaninaite
Relationship of Sekaninaite to other Species
Forms a series with:
Common Associates
Associated Minerals Based on Photo Data:
2 photos of Sekaninaite associated with Microcline | K(AlSi3O8) |
1 photo of Sekaninaite associated with Orthoclase | K(AlSi3O8) |
Related Minerals - Strunz-mindat Grouping
9.CJ. | Zolotarevite | Na5Zr[Si6O15(OH)3] · 3H2O |
9.CJ. | Avdeevite | NaAl4(Be5Li)(Si6O18)2(H2O)1-2 |
9.CJ. | Beryllocordierite-Na | NaMg4(Al5Be)(AlSi5O18)2 · 2H2O |
9.CJ. | Beryllosachanbińskiite-Na | NaMn4(Al5Be)(AlSi5O18)2 · 2H2O |
9.CJ. | Nakkaalaaqite | K2[Na3Ca]LiCa2Ti2Be4Si12O38 |
9.CJ.05 | Johnkoivulaite | Cs[Be2B]Mg2Si6O18 |
9.CJ.05 | Beryl | Be3Al2(Si6O18) |
9.CJ.05 | Bazzite | Be3Sc2(Si6O18) |
9.CJ.05 | Ferroindialite | (Fe2+,Mg)2Al4Si5O18 |
9.CJ.05 va | Vorobyevite | Be3Al2(Si6O18) |
9.CJ.05 | Stoppaniite | Be3Fe3+2(Si6O18) · H2O |
9.CJ.05 | Indialite | Mg2Al3(AlSi5O18) |
9.CJ.10 | Cordierite | (Mg,Fe)2Al3(AlSi5O18) |
9.CJ.15a | Zirsinalite | Na6(Ca,Mn2+,Fe2+)Zr(Si6O18) |
9.CJ.15a | Kapustinite | Na6ZrSi6O16(OH)2 |
9.CJ.15a | Townendite | Na8ZrSi6O18 |
9.CJ.15a | Combeite | Na4.5Ca3.5Si6O17.5(OH)0.5 |
9.CJ.15a | Kazakovite | Na6Mn2+Ti(Si6O18) |
9.CJ.15a | Tisinalite | Na3H3(Mn,Ca,Fe)TiSi6(O,OH)18 · 2H2O |
9.CJ.15a | Lovozerite | Na2Ca(Zr,Ti)(Si6O12)[(OH)4O2] · H2O |
9.CJ.15a | Litvinskite | Na2(◻,Na,Mn)ZrSi6O12(OH,O)6 |
9.CJ.15c | Koashvite | Na6(Ca,Mn)(Ti,Fe)Si6O18 · H2O |
9.CJ.15b | Imandrite | Na12Ca3Fe3+2(Si6O18)2 |
9.CJ.25 | Baratovite | KCa7(Ti,Zr)2Li3Si12O36F2 |
9.CJ.25 | Aleksandrovite | KCa7Sn2Li3Si12O36F2 |
9.CJ.25 | Katayamalite | KLi3Ca7Ti2(SiO3)12(OH)2 |
9.CJ.30 | Dioptase | CuSiO3 · H2O |
9.CJ.35 | Kostylevite | K2Zr(Si3O9) · H2O |
9.CJ.40 | Petarasite | Na5Zr2(Si6O18)(Cl,OH) · 2H2O |
9.CJ.45 | Gerenite-(Y) | (Ca,Na)2(Y,REE)3Si6O18 · 2H2O |
9.CJ.50 | Odintsovite | K2Na4Ca3Ti2Be4Si12O38 |
9.CJ.55 | Mathewrogersite | Pb7FeAl3GeSi12O36(OH,H2O)6 |
9.CJ.60 | Pezzottaite | Cs(Be2Li)Al2(Si6O18) |
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 Sekaninaite
mindat.org URL:
https://www.mindat.org/min-3609.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Sekaninaite
Reference List:
Hochella, Michael F., Brown, Gordon E., Ross, Fred K., Gibbs, G. V. (1979) High-temperature crystal chemistry of hydrous Mg- and Fe-cordierites. American Mineralogist, 64 (3-4) 337-351
Ryback, George, Nawaz, R., Farley, E. (1988) Seventh supplementary list of British Isles minerals (Irish) Mineralogical Magazine, 52 (365) 267-274
Yakubovich, O. V., Massa, V., Pekov, I. V., Gavrilenko, P. G., Chukanov, N. V. (2004) Crystal structure of the Na-, Ca-, Be-cordierite and crystallochemical regularities in the cordierite—sekaninaite series. Crystallography Reports, 49 (6) 953-963 doi:10.1134/1.1828139
Kaindl, R., Tobbens, D. M., Haefeker, U. (2011) Quantum-mechanical calculations of the Raman spectra of Mg- and Fe-cordierite. American Mineralogist, 96 (10) 1568-1574 doi:10.2138/am.2011.3845
Radica, F., Capitelli, F., Bellatreccia, F., Della Ventura, G., Cavallo, A., Piccinini, M., Hawthorne, F. C. (2013) Spectroscopy and X-ray structure refinement of sekaninaite from Dolní Bory (Czech Republic) Mineralogical Magazine, 77 (4) 485-498 doi:10.1180/minmag.2013.077.4.08
Haefeker, Udo, Kaindl, Reinhard, Tropper, Peter, Krüger, Hannes, Kahlenberg, Volker, Orlova, Maria (2014) Structural investigations of the two polymorphs of synthetic Fe-cordierite and Raman spectroscopy of hexagonal Fe-cordierite. Mineralogy and Petrology, 108 (4) 469-478 doi:10.1007/s00710-013-0313-3
Dixon, Andrea, Cempírek, Jan, Groat, Lee A. (2014) Mineralogy and geochemistry of pegmatites on Mount Begbie, British Columbia. The Canadian Mineralogist, 52 (2). 129-164 doi:10.3749/canmin.52.2.129
Novák, Milan, Čopjaková, Renata, Dosbaba, Marek, Galiová, Michaela VAŠINOVÁ, Všianský, Dalibor, Staněk, Josef (2015) Two Paragenetic Types of Cookeite From the Dolní Bory-Hatě Pegmatites, Moldanubian Zone, Czech Republic: Proximal and Distal Alteration Products of Li-Bearing Sekaninaite. The Canadian Mineralogist, 53 (6) 1035-1048 doi:10.3749/canmin.1400090
Localities for Sekaninaite
Locality List




All localities listed without proper references should be considered as questionable.
Australia | |
| Bottrill +1 other reference |
| Birch et al. (2025) |
Austria | |
| Taucher et al. (1998) |
Brazil | |
| Fernandes et al. (2022) |
Canada | |
| Dixon et al. (2014) +1 other reference |
| D. Doell collection |
Czech Republic | |
| Škoda et al. (2004) |
| Žáček V |
| Houzar S.: Minerální asociace ... |
| Scr.Fac.Sci.Nat. Ujep Brun. (1975) +1 other reference |
Staněk (1997) | |
Staněk (1997) +1 other reference | |
| Staněk (1997) |
Staněk (1997) | |
Finland | |
| Hytönen (1999) |
| Ilkka Mikkola |
Germany | |
| Keck et al. (2010) |
| Schnorrer et al. (2000) |
| in the collection of Christof Schäfer |
Italy | |
| Piccoli et al. (2007) |
| Grill (1935) |
Guastoni et al. (2004) | |
| Bosi et al. (2018) |
| Orlandi P. (1994) |
Orlandi et al. (1997) | |
Japan | |
| Masutomi Museum specimens +1 other reference |
| Introduction to Japanese Minerals (Geological Survey of Japan, 1970) |
| Yamada (2004) |
| American Mineralogist 87: 160-170 (2002) |
Mongolia | |
| Savina et al. (2020) +1 other reference |
North America Plate | |
Reidel et al. (2022) | |
Peru | |
| Yáñez et al. (2014, May) |
Poland | |
| 86. +2 other references |
| Ł. Kruszewski EPMA/PXRD data +1 other reference |
Russia | |
| Cesnokov et al. (1998) |
| Filimonova et al. (2008) |
| Olga Yakovleva et al. (2009) |
Ivanyuk et al. (2007) | |
Yakovenchuk et al. (2008) | |
Slovakia | |
| Košuth M. |
| Ďuďa |
Sweden | |
| Damman (1989) |
Tajikistan | |
| Sharygin et al. (2009) |
UK | |
| Wilson et al. (1966) +1 other reference |
USA | |
| Stephen P. Reidel and Martin E. Ross (2022) |
| Anderson |
| Cristofono (n.d.) |
| Harvard Mineralogical Museum |
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Dolní Bory, Bory, Žďár nad Sázavou District, Vysočina Region, Czech Republic