Ekplexite
A valid IMA mineral species
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Formula:
(Nb,Mo,W)S2 · (Mg1-xAlx)(OH)2+x
Colour:
Iron-black
Lustre:
Metallic
Hardness:
1
Specific Gravity:
3.63 (Calculated)
Crystal System:
Trigonal
Member of:
Name:
From the Greek έκπληξις ("ekplexis") = surprise, apparently alluding to the surprising combination of elements in its chemical formula.
Type Locality:
This page provides mineralogical data about Ekplexite.
Unique Identifiers
Mindat ID:
42864
Long-form identifier:
mindat:1:1:42864:6
IMA Classification of Ekplexite
Approved
IMA Formula:
(Nb5+,Mo)S2·(Mg1-xAlx)(OH)2+x
Approval year:
2011
First published:
2014
Type description reference:
Pekov, I. V., Yapaskurt, V. O., Polekhovsky, Y. S., Vigasina, M. F., Siidra, O. I. (2014) Ekplexite (Nb,Mo)S2·(Mg1−xAlx)(OH)2+x, kaskasite (Mo,Nb)S2·(Mg1−xAlx)(OH)2+x and manganokaskasite
(Mo,Nb)S2·(Mn1−xAlx)(OH)2+x, three new valleriite-group mineral species from the Khibiny alkaline
complex, Kola peninsula, Russia. Mineralogical Magazine, 78 (3) 663-679 doi:10.1180/minmag.2014.078.3.14
Classification of Ekplexite
2.FD.30
2 : SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulfantimonites, sulfbismuthites, etc.)
F : Sulfides of arsenic, alkalies; sulfides with halide, oxide, hydroxide, H2O
D : With O, OH, H2O
2 : SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulfantimonites, sulfbismuthites, etc.)
F : Sulfides of arsenic, alkalies; sulfides with halide, oxide, hydroxide, H2O
D : With O, OH, H2O
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 |
|---|---|---|
| Ekp | 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 Ekplexite
Metallic
Transparency:
Opaque
Colour:
Iron-black
Hardness:
1 on Mohs scale
Tenacity:
Flexible
Cleavage:
Perfect
{001} perfect
{001} perfect
Density:
3.63 g/cm3 (Calculated)
Chemistry of Ekplexite
Mindat Formula:
(Nb,Mo,W)S2 · (Mg1-xAlx)(OH)2+x
Crystallography of Ekplexite
Crystal System:
Trigonal
Cell Parameters:
a = 3.791(3) Å, c = 11.30(1) Å
Ratio:
a:c = 1 : 2.981
Unit Cell V:
140.64 ų (Calculated from Unit Cell)
Morphology:
Mical-like flakes in aggregates.
Comment:
Space group: P321, P3m1 or P3¯ m1
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 11.37 Å | (100) |
| 5.65 Å | (55) |
| 3.155 Å | (4) |
| 2.809 Å | (20) |
| 1.623 Å | (11) |
Reference:
Pekov, I. V., Yapaskurt, V. O., Polekhovsky, Y. S., Vigasina, M. F., Siidra, O. I. (2014) Ekplexite (Nb,Mo)S2·(Mg1−xAlx)(OH)2+x, kaskasite (Mo,Nb)S2·(Mg1−xAlx)(OH)2+x and manganokaskasite
(Mo,Nb)S2·(Mn1−xAlx)(OH)2+x, three new valleriite-group mineral species from the Khibiny alkaline
complex, Kola peninsula, Russia. Mineralogical Magazine, 78 (3) 663-679 doi:10.1180/minmag.2014.078.3.14
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 4b: Highly evolved igneous rocks | >3.0 |
| 35 : Ultra-alkali and agpaitic igneous rocks | |
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] |
Type Occurrence of Ekplexite
General Appearance of Type Material:
Lenticular nests up to 0.2 mm×1 mm×1 mm consisting of near-parallel, radiating or chaotic aggregates of soft flakes.
Place of Conservation of Type Material:
Fersman Mineralogical Museum of the Russian Academy of Sciences, Moscow, Russia, registration number 4155/1
Geological Setting of Type Material:
In perthite-rich fenite, Khibiny alkaline complex, Russia.
Associated Minerals at Type Locality:
Reference:
Pekov, I. V., Yapaskurt, V. O., Polekhovsky, Y. S., Vigasina, M. F., Siidra, O. I. (2014) Ekplexite (Nb,Mo)S2·(Mg1−xAlx)(OH)2+x, kaskasite (Mo,Nb)S2·(Mg1−xAlx)(OH)2+x and manganokaskasite
(Mo,Nb)S2·(Mn1−xAlx)(OH)2+x, three new valleriite-group mineral species from the Khibiny alkaline
complex, Kola peninsula, Russia. Mineralogical Magazine, 78 (3) 663-679 doi:10.1180/minmag.2014.078.3.14
Synonyms of Ekplexite
Other Language Names for Ekplexite
Relationship of Ekplexite to other Species
Member of:
Other Members of Valleriite Group:
| Ferrotochilinite | Fe2+6(Fe2+,Mg)5S6(OH)10 | Mon. |
| Ferrovalleriite | 2(Fe,Cu)S · 1.5Fe(OH)2 | Trig. |
| Haapalaite | (Fe2+,Ni)2(Mg,Fe2+)1.61S2(OH)3.22 | Hex. |
| Tochilinite | Fe2+5-6(Mg,Fe2+)5S6(OH)10 | Mon. |
| Valleriite | (Fe2+,Cu)4(Mg,Al)3S4(OH,O)6 | Trig. |
| Yushkinite | (Mg,Al)V4+S2(OH)2 | Trig. 3m(32/m) : P3m1 |
Related Minerals - Strunz-mindat Grouping
| 2.FD. | Ferrovalleriite | 2(Fe,Cu)S · 1.5Fe(OH)2 |
| 2.FD.05 | Kermesite | Sb2S2O |
| 2.FD.10 | Viaeneite | (Fe,Pb)4S8O |
| 2.FD.20 | Erdite | NaFeS2 · 2H2O |
| 2.FD.25 | Coyoteite | NaFe3S5 · 2H2O |
| 2.FD.30 | Yushkinite | (Mg,Al)V4+S2(OH)2 |
| 2.FD.30 | Valleriite | (Fe2+,Cu)4(Mg,Al)3S4(OH,O)6 |
| 2.FD.30 | Haapalaite | (Fe2+,Ni)2(Mg,Fe2+)1.61S2(OH)3.22 |
| 2.FD.35 | Kaskasite | (Mo,Nb)S2 · (Mg1-xAlx)(OH)2+x |
| 2.FD.35 | Manganokaskasite | (Mo,Nb)S2 · (Mn1-xAlx)(OH)2+x |
| 2.FD.35 | Tochilinite | Fe2+5-6(Mg,Fe2+)5S6(OH)10 |
| 2.FD.35 | Ferrotochilinite | Fe2+6(Fe2+,Mg)5S6(OH)10 |
| 2.FD.40 | Wilhelmramsayite | Cu3FeS3 · 2H2O |
| 2.FD.45 | Vyalsovite | FeCaAlS(OH)5 |
| 2.FD.50 | Bazhenovite | Ca8S2(S3)(S2O3)(OH)12 · 20H2O |
| 2.FD.55 | 'UM2004-56-OS:BiCuPb' | PbCu4Bi4S2(O,OH,H2O)16 (?) |
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 Ekplexite
mindat.org URL:
https://www.mindat.org/min-42864.html
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References for Ekplexite
Reference List:
Williams, P. A., Hatert, F., Pasero, M., Mills, S. J. (2012) New minerals and nomenclature modifications approved in 2012. CNMNC Newsletter No 12. Mineralogical Magazine, 76 (1) 151-155 doi:10.1180/minmag.2012.076.1.151
Pekov, I. V., Yapaskurt, V. O., Polekhovsky, Y. S., Vigasina, M. F., Siidra, O. I. (2014) Ekplexite (Nb,Mo)S2·(Mg1−xAlx)(OH)2+x, kaskasite (Mo,Nb)S2·(Mg1−xAlx)(OH)2+x and manganokaskasite
(Mo,Nb)S2·(Mn1−xAlx)(OH)2+x, three new valleriite-group mineral species from the Khibiny alkaline
complex, Kola peninsula, Russia. Mineralogical Magazine, 78 (3) 663-679 doi:10.1180/minmag.2014.078.3.14
Localities for Ekplexite
Showing 1 localities.
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.
Russia (TL) | |
| Williams et al. (2012) +1 other reference |
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