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Neskevaaraite-Fe

A valid IMA mineral species
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About Neskevaaraite-FeHide

Formula:
K3Na2Fe2+(Ti,Nb)4(Si4O12)2(O,OH)4 · 5-6 H2O
Colour:
Pale brown to yellowish brown
Lustre:
Vitreous
Hardness:
5
Specific Gravity:
2.88
Crystal System:
Monoclinic
Name:
For Neskevaara Hill, Russia, the type locality. The suffix (modifier) follows the naming convention for labuntsovite supergroup minerals, indicating that iron is the dominant extra-framework cation.
This page provides mineralogical data about Neskevaaraite-Fe.


Unique IdentifiersHide

Mindat ID:
25590
Long-form identifier:
mindat:1:1:25590:7

IMA Classification of Neskevaaraite-FeHide

Approved
IMA Formula:
NaK3Fe2+(Ti4+,Nb5+)4(Si4O12)2(O,OH)4·6H2O
Approval year:
2002
First published:
2003

Classification of Neskevaaraite-FeHide

9.CE.30h

9 : SILICATES (Germanates)
C : Cyclosilicates
E : [Si4O12]8- 4-membered single rings (vierer-Einfachringe), without insular complex anions

Mineral SymbolsHide

As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.

SymbolSourceReference for Standard
Nsv-FeIMA–CNMNCWarr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43

Physical Properties of Neskevaaraite-FeHide

Vitreous
Transparency:
Translucent, Opaque
Colour:
Pale brown to yellowish brown
Streak:
White
Hardness:
Tenacity:
Brittle
Cleavage:
None Observed
Fracture:
Irregular/Uneven
Density:
2.88(3) g/cm3 (Measured)    2.90 g/cm3 (Calculated)

Optical Data of Neskevaaraite-FeHide

Type:
Biaxial (+)
RI values:
nα = 1.677(1) nβ = 1.684(2) nγ = 1.790(5)
2V:
Measured: 25° (10)
Max. Birefringence:
δ = 0.113
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.

Surface Relief:
Very High (positive)
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.
Optical Extinction:
Y = b.
Pleochroism:
Not Visible

Chemistry of Neskevaaraite-FeHide

Mindat Formula:
K3Na2Fe2+(Ti,Nb)4(Si4O12)2(O,OH)4 · 5-6 H2O
Element Weights:
Element% weight
O44.998 %
Si19.149 %
Ti16.318 %
K9.997 %
Fe4.760 %
Na3.919 %
H0.859 %

Calculated from ideal end-member formula.
O
Si
Ti
K
Fe
Na
H

Crystallography of Neskevaaraite-FeHide

Crystal System:
Monoclinic
Class (H-M):
m - Domatic
Space Group:
Bm
Setting:
Cm
Cell Parameters:
a = 14.45 Å, b = 13.91 Å, c = 7.836 Å
β = 117.42°
Ratio:
a:b:c = 1.039 : 1 : 0.563
Unit Cell V:
1,398.08 ų (Calculated from Unit Cell)
Morphology:
{201}, {100}, {101}, {001}, {021}, crystals elongated along [010].

Epitaxial Relationships of Neskevaaraite-FeHide

Epitaxial Minerals:
'Labuntsovite-Fe'Na4K4(Ba,K)2Fe2+(Ti,Nb)8(Si4O12)4(O,OH)8 · 10H2O
Epitaxy Comments:
Parallel to {100}

X-Ray Powder DiffractionHide

Powder Diffraction Data:
d-spacingIntensity
6.93 Å(100)
4.93 Å(80)
3.21 Å(100)
3.11 Å(90)

Geological EnvironmentHide

Paragenetic Mode(s):
Paragenetic ModeEarliest Age (Ga)
Stage 4b: Highly evolved igneous rocks>3.0
35 : Ultra-alkali and agpaitic igneous rocks

Type Occurrence of Neskevaaraite-FeHide

General Appearance of Type Material:
Prismatic crystals to 6 mm.
Place of Conservation of Type Material:
A.E. Fersman Mineralogical Museum, Russian Academy of Science, Moscow, Russia; 2814/1.
Geological Setting of Type Material:
Hydrothermally altered carbonatite.
Associated Minerals at Type Locality:

Synonyms of Neskevaaraite-FeHide

Other Language Names for Neskevaaraite-FeHide

Simplified Chinese:碱硅钛铁石
Traditional Chinese:鹼矽鈦鐵石

Relationship of Neskevaaraite-Fe to other SpeciesHide

Other Members of Gutkovaite Group:
Alsakharovite-ZnNaSrKZn(Ti,Nb)4(Si4O12)2(O,OH)4 · 7H2OMon. m : Bm
Gutkovaite-MnK2CaMn(Ti,Nb)4(Si4O12)2(O,OH)4 · 5H2OMon. m : Bm

Common AssociatesHide

Associations Based on Photo Data:
1 photo of Neskevaaraite-Fe associated with Labuntsovite-FeNa4K4(Ba,K)2Fe2+(Ti,Nb)8(Si4O12)4(O,OH)8 · 10H2O

Related Minerals - Strunz-mindat GroupingHide

9.CE.Dutkevichite-(Ce)NaZnBa2Ce2Ti2Si8O26F · H2OOrth. mm2 : Ama2
9.CE.KataniteBa3NbFe3Si2O14Trig. 32 : P321
9.CE.NiobobaotiteBa4(Ti2.5Fe2+1.5)Nb4Si4O28ClTet. 4/m : I41/a
9.CE.AmaterasuiteSr4Ti6Si4O23(OH)ClOrth. mmm(2/m2/m2/m) : Fddd
9.CE.SteiningeriteBa2Zr2(Si4O12)O2Tet. 4/mmm(4/m2/m2/m) : P4/mbm
9.CE.05PapagoiteCaCu[H3AlSi2O9]Mon. 2/m : B2/m
9.CE.10VerplanckiteBa4Mn2+2Si4O12(OH,H2O)3Cl3Hex. 6/mmm(6/m2/m2/m) : P6/mmm
9.CE.15BaotiteBa4(Ti,Nb,W)8O16(SiO3)4ClTet. 4/m : I41/a
9.CE.20NagashimaliteBa4(V,Ti)4B2Si8O27(O,OH)2ClOrth. mmm(2/m2/m2/m) : Pmmn
9.CE.20TaramelliteBa4(Fe3+,Ti,Fe2+,Mg)4(B2Si8O27)O2ClxOrth. mmm(2/m2/m2/m) : Pmmn
9.CE.20TitantaramelliteBa4(Ti,Fe3+,Fe2+,Mg)4(B2Si8O27)O2ClxOrth. mmm(2/m2/m2/m)
9.CE.25Bario-orthojoaquinite(Ba,Sr)4Fe2Ti2[Si4O12]2O2 · H2OOrth.
9.CE.25Byelorussite-(Ce)NaBa2Ce2MnTi2[Si4O12]2O2(F,OH) · H2OOrth. mm2 : Ama2
9.CE.25Joaquinite-(Ce)NaBa2Ce2FeTi2[Si4O12]2O2(OH,F) · H2OMon. 2 : B2
9.CE.25Orthojoaquinite-(La)NaBa2La2Fe2+Ti2[Si4O12]2O2(O,OH) · H2OOrth. mmm(2/m2/m2/m)
9.CE.25StrontiojoaquiniteSr2Ba2(Na,Fe)2Ti2[Si4O12]2O2(O,OH)2 · H2OMon.
9.CE.25Orthojoaquinite-(Ce)NaBa2Ce2FeTi2[Si4O12]2O2(O,OH) · H2OOrth.
9.CE.25Strontio-orthojoaquinite(Na,Fe)2Sr2Ba2Ti2[Si4O12]2O2(O,OH)2 · H2OOrth.
9.CE.30eLabuntsovite-MnNa4K4(Ba,K)2Mn2+(Ti,Nb)8(Si4O12)4(O,OH)8 · 10-12H2OMon. 2/m : B2/m
9.CE.30bTsepinite-NaNa2(Ti,Nb)2(Si4O12)(OH,O)2 · 3H2OMon. m : Bm
9.CE.30cGjerdingenite-NaK2Na(Nb,Ti)4(Si4O12)2(OH,O)4 · 5H2OMon. 2/m : B2/m
9.CE.30hAlsakharovite-ZnNaSrKZn(Ti,Nb)4(Si4O12)2(O,OH)4 · 7H2OMon. m : Bm
9.CE.30cBurovaite-Ca(Na,K)4Ca2(Ti,Nb)8(Si4O12)4(OH,O)8 · 12H2OMon. 2/m : B2/m
9.CE.30aNenadkevichite(Na,◻)8Nb4(Si4O12)2(O,OH)4 · 8H2OOrth. mmm(2/m2/m2/m) : Pbam
9.CE.30bTsepinite-SrSr(Ti,Nb)2(Si4O12)(OH,O)2 · 3H2OMon. m : Bm
9.CE.30cGjerdingenite-MnK2Mn2+(Nb,Ti)4(Si4O12)2(O,OH)4 · 6H2OMon. 2/m : B2/m
9.CE.30bParatsepinite-Na(Na,Sr,K,Ca)7(Ti,Nb)8(Si4O12)4(O,OH)8 · nH2O n ~ 8Mon. 2/m : B2/m
9.CE.30dLemmleinite-KK2(Ti,Nb)2(Si4O12)(OH,O)2 · 4H2OOrth.
9.CE.30cKarupmøllerite-Ca(Na,Ca,K)2Ca(Nb,Ti)4(Si4O12)2(O,OH)4 · 7H2OMon. 2/m : B2/m
9.CE.30cLepkhenelmite-Zn(Ba,K)2Zn(Ti,Nb)4(Si4O12)2(O,OH)4 · 7H2OMon. m : Bm
9.CE.30hGutkovaite-MnK2CaMn(Ti,Nb)4(Si4O12)2(O,OH)4 · 5H2OMon. m : Bm
9.CE.30eLabuntsovite-MgNa4K4(Ba,K)2Mg(Ti,Nb)8(Si4O12)4(O,OH)8 · 10H2OMon. 2/m : B2/m
9.CE.30eLabuntsovite-FeNa4K4(Ba,K)2Fe2+(Ti,Nb)8(Si4O12)4(O,OH)8 · 10H2OMon. 2/m : B2/m
9.CE.30cKuzmenkoite-ZnK2Zn(Ti,Nb)4(Si4O12)2(OH,O)4 · 6-8H2OMon. m : Bm
9.CE.30fParalabuntsovite-MgNa8K8Mg4Ti16(Si4O12)8(OH,O)16 · 20-24H2OMon. 2/m : B2/m
9.CE.30dLemmleinite-BaNa2K2Ba(Ti,Nb)4(Si4O12)2(O,OH)4 · 5H2OMon. 2/m : B2/m
9.CE.30gOrganovaite-MnK2Mn(Nb,Ti)4(Si4O12)2(O,OH)4 · 5-7H2OMon. 2/m : B2/m
9.CE.30gOrganovaite-ZnK2Zn(Nb,Ti)4(Si4O12)2(O,OH)4 · 6H2OMon. 2/m : B2/m
9.CE.30bVuoriyarvite-KK2(Nb,Ti)2(Si4O12)(O,OH)2 · 4H2OMon. m : Bm
9.CE.30cGjerdingenite-FeK2Fe2+(Nb,Ti)4(Si4O12)2(O,OH)4 · 6H2OMon. 2/m : B2/m
9.CE.30a'Unnamed (Ca-Na-ordered analogue of Korobitsynite)'(Ca,Na)2(Ti,Nb)2(Si4O12)(OH,O)2 · 3-4H2OOrth. 222 : P21212
9.CE.30gParakuzmenkoite-Fe(K,Ba)4Fe(Ti,Nb)8(Si4O12)4(O,OH)8 · 14H2OMon. 2/m : B2/m
9.CE.30aKorobitsynite(Na,◻)4Ti2(Si4O12)(O,OH)2 · 4H2OOrth. mmm(2/m2/m2/m) : Pbam
9.CE.30cKuzmenkoite-MnK2Mn2+(Ti,Nb)4(Si4O12)2(OH,O)4 · 5-6H2OMon. 2/m : B2/m
9.CE.30bTsepinite-KK2(Ti,Nb)2(Si4O12)(OH,O)2 · 3H2OMon. m : Bm
9.CE.30bParatsepinite-BaBa4(Ti,Nb)8(Si4O12)4(OH,O)8 · 8H2OMon. 2/m : B2/m
9.CE.30cGjerdingenite-CaK2Ca(Nb,Ti)4(Si4O12)2(O,OH)4 · 6H2OMon. 2/m : B2/m
9.CE.30bTsepinite-Ca(Ca,K,Na)2-x(Ti,Nb)2(Si4O12)(OH,O)2 · 4H2OMon. 2/m : B2/m
9.CE.45'Natrokomarovite'(Na,Ca,H)2Nb2Si2O10(OH,F)2 · H2OOrth.
9.CE.45Komarovite(Ca,Mn)(Nb,Ti)2[Si2O7](O,F)3 · 3.5H2OOrth. mmm(2/m2/m2/m) : Cmmm

RadioactivityHide

Radioactivity:
Element % Content Activity (Bq/kg) Radiation Type
Uranium (U) 0.0000% 0 α, β, γ
Thorium (Th) 0.0000% 0 α, β, γ
Potassium (K) 9.9967% 3,099 β, γ

For comparison:

  • Banana: ~15 Bq per fruit
  • Granite: 1,000–3,000 Bq/kg
  • EU exemption limit: 10,000 Bq/kg

Note: Risk is shown relative to daily recommended maximum exposure to non-background radiation of 1000 µSv/year. Note that natural background radiation averages around 2400 µSv/year so in reality these risks are probably extremely overstated! With infrequent handling and safe storage natural radioactive minerals do not usually pose much risk.

Interactive Simulator:

Note: The mass selector refers to the mass of radioactive mineral present, not the full specimen, also be aware that the matrix may also be radioactive, possibly more radioactive than this mineral!

Activity: –

DistanceDose rateRisk
1 cm
10 cm
1 m

The external dose rate (D) from a radioactive mineral is estimated by summing the gamma radiation contributions from its Uranium, Thorium, and Potassium content, disregarding daughter-product which may have a significant effect in some cases (eg 'pitchblende'). This involves multiplying the activity (A, in Bq) of each element by its specific gamma ray constant (Γ), which accounts for its unique gamma emissions. The total unshielded dose at 1 cm is then scaled by the square of the distance (r, in cm) and multiplied by a shielding factor (μshield). This calculation provides a 'worst-case' or 'maximum risk' estimate because it assumes the sample is a point source and entirely neglects any self-shielding where radiation is absorbed within the mineral itself, meaning actual doses will typically be lower. The resulting dose rate (D) is expressed in microsieverts per hour (μSv/h).

D = ((AU × ΓU) + (ATh × ΓTh) + (AK × ΓK)) / r2 × μshield

Fluorescence of Neskevaaraite-FeHide

Other InformationHide

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 Neskevaaraite-FeHide

References for Neskevaaraite-FeHide

Localities for Neskevaaraite-FeHide

Showing 2 localities.

This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.
Hide all sections | Show all sections

Locality ListHide

- 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). Struck out - Mineral was erroneously reported from this locality. Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).

All localities listed without proper references should be considered as questionable.
Russia
 
  • Murmansk Oblast
    • Kukisvumchorr Mt
Lapis 28 (12) +1 other reference
    • Northern Karelia
      • Vuoriyarvi alkaline-ultrabasic massif
Chukanov et al. (2003) +1 other reference
 
and/or  
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