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Sosedkoite

A valid IMA mineral species
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03802250017271926631471.jpg
Alexander F. Sosedko
Formula:
(K,Na)5Al2(Ta,Nb)22O60
Colour:
Colourless
Lustre:
Adamantine
Hardness:
6
Specific Gravity:
6.90 (Calculated)
Crystal System:
Orthorhombic
Name:
Named after Alexander Fedorovich Sosedko (Александр Федорович Соседко) (12 September 1901 - 1957), mineralogist, Institute of Geological Sciences, Academy of Sciences of the USSR (Moscow). He was a specialist in granite pegmatites.
This page provides mineralogical data about Sosedkoite.


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Unique IdentifiersHide

Mindat ID:
3717
Long-form identifier:
mindat:1:1:3717:0

IMA Classification of SosedkoiteHide

Classification of SosedkoiteHide

4.DM.05

4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
D : Metal: Oxygen = 1:2 and similar
M : With large (+- medium-sized) cations; unclassified
8.7.6.2

8 : MULTIPLE OXIDES CONTAINING NIOBIUM,TANTALUM OR TITANIUM
7 : Miscellaneous
18.1.20

18 : Niobates and Tantalates
1 : Niobates and tantalates containing neither rare earths nor U

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

Physical Properties of SosedkoiteHide

Adamantine
Transparency:
Transparent
Colour:
Colourless
Streak:
White
Hardness:
Hardness:
VHN20=800 - 860 kg/mm2 - Vickers
Cleavage:
None Observed
Density:
6.90 g/cm3 (Calculated)

Optical Data of SosedkoiteHide

Type:
Biaxial
Anisotropism:
Strong
Bireflectance:
Strong
Reflectivity:
WavelengthR1 (%)R2 (%)
486nm13.5%12.8%
551nm12.8%12.0%
589nm13.3%12.3%
656nm11.3%11.3%


Graph shows reflectance levels at different wavelengths (in nm). Peak reflectance is 13.5%.
R1 shown in black, R2 shown in red

Chemistry of SosedkoiteHide

Mindat Formula:
(K,Na)5Al2(Ta,Nb)22O60
Element Weights:
Element% weight
Ta76.698 %
O18.495 %
K3.767 %
Al1.040 %

Calculated from ideal end-member formula.
Common Impurities:
Sb

Crystallography of SosedkoiteHide

Crystal System:
Orthorhombic
Cell Parameters:
a = 17.25(3) Å, b = 17.73(3) Å, c = 3.95(2) Å
Ratio:
a:b:c = 0.973 : 1 : 0.223
Unit Cell V:
1,208.08 ų (Calculated from Unit Cell)
Z:
1
Comment:
Point Group: n.d.; Space Group: n.d.

X-Ray Powder DiffractionHide

Powder Diffraction Data:
d-spacingIntensity
3.95 Å(100)
3.03 Å(90)
1.974 Å(60)
6.1 Å(50)
3.47 Å(50)
2.79 Å(50)
2.376 Å(50)
Comments:
Vasin-Myl'k Mt, Murmansk Oblast, Russia. The data are from the type description.

Geological EnvironmentHide

Paragenetic Mode(s):
Paragenetic ModeEarliest Age (Ga)
Stage 4b: Highly evolved igneous rocks>3.0
34 : Complex granite pegmatites

Type Occurrence of SosedkoiteHide

General Appearance of Type Material:
Acicular crystals up to 0.1 mm long in microlite and in hydroxykenomicrolite (cesstibtantite) and along grain boundaries of those minerals.
Place of Conservation of Type Material:
Geology Museum, Kola Branch, Academy of Sciences, Apatity, Russia, 5518.
Mining Museum, St. Petersburg, Russia, 2099/1.
A.E. Fersman Mineralogical Museum, Academy of Sciences, Moscow, Russia.
Geological Setting of Type Material:
Granite pegmatite
Associated Minerals at Type Locality:

Synonyms of SosedkoiteHide

Other Language Names for SosedkoiteHide

German:Sosedkoit
Spanish:Sosedkoita

Related Minerals - Strunz-mindat GroupingHide

4.DM.SugarwhiteitePb2Te5O12Mon. 2/m : P21/b
4.DM.ZuoliniteBa2Sr(Nb4.5Fe3+0.5)O15Tet. 4/mmm(4/m2/m2/m) : P4/mbm
4.DM.BahariyaiteKMnO4Orth. mmm(2/m2/m2/m) : Pnma
4.DM.05Rankamaite(Na,K)3(Ta,Nb,Al)11(O,OH)31Orth. mmm(2/m2/m2/m) : Cmmm
4.DM.15Cesplumtantite(Cs,Na)2(Pb,Sb3+)3Ta8O24Tet.
4.DM.20EyseliteFe3+Ge4+3O7(OH)Orth.
4.DM.25KonzettiteCaMn4+Te6+O6Trig. 32 : P312
4.DM.25KuranakhitePbMn4+Te6+O6Orth.
4.DM.30MambertiiteBiMo5+2.80O8(OH)Tric. 1 : P1
4.DM.30GelosaiteBiMo6+(2-5x)Mo5+6xO7(OH) · H2O Mon. 2/m : P21/m
4.DM.35EkebergiteThFeNb2O8Mon. 2/m : P2/b
4.DM.45RiesiteTiO2Mon. 2/m : P2/b
4.DM.50SardignaiteBiMo2O7(OH) · 2H2OMon. 2/m : P21/m
4.DM.55Tewite(K1.50.5)(Te1.25W0.250.5)W5O19Orth. mmm(2/m2/m2/m) : Pban
4.DM.60WumuiteK(W2.67Al0.33)O9Hex. 6/mmm(6/m2/m2/m) : P6/mmm
4.DM.60KingsgateiteZrMo6+2O7(OH)2 · 2H2OTet. 4mm : I41cd
4.DM.60MorningstariteNa(W2.67Fe3+0.33)O9 · H2OHex. 6/mmm(6/m2/m2/m) : P6/mmm

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) 3.7665% 1,168 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

Other InformationHide

Notes:
Faint blue cathodoluminescence.
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 SosedkoiteHide

References for SosedkoiteHide

Localities for SosedkoiteHide

Showing 1 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.
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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 (TL)
 
  • Murmansk Oblast
    • Voron'i Tundry
Voloshin et al. (1982) +2 other references
 
and/or  
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