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Polyakovite-(Ce) Mineral Data

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General Polyakovite-(Ce) Information

Help on Chemical  Formula: Chemical Formula: (Ce,La,Nd,Pr,Ca)4(Mg,Fe++)(Cr,Fe+++)2(Ti,Nb)2Si4O22
Help on Composition: Composition: Molecular Weight = 1,255.42 gm
   Calcium         0.64 %  Ca    0.89 % CaO
   Lanthanum      13.28 %  La   15.57 % La2O3
   Cerium         21.21 %  Ce   24.84 % Ce2O3
   Praeseodymium   2.24 %  Pr    2.63 % Pr2O3
   Thorium         1.85 %  Th    2.10 % ThO2
   Magnesium       1.55 %  Mg    2.57 % MgO
   Titanium        5.72 %  Ti    9.54 % TiO2
   Niobium         2.96 %  Nb    4.23 % Nb2O5
   Chromium        4.97 %  Cr    7.26 % Cr2O3
   Iron            4.00 %   Fe    1.14 % FeO /  4.45 % Fe2O3
   Silicon         8.95 %  Si   19.14 % SiO2
   Neodymium       4.60 %  Nd    5.36 % Nd2O3
   Oxygen         28.04 %  O
                 ______        ______ 
                 100.00 %       99.75 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Ce1.9La1.2Nd0.4Pr0.2Ca0.2Th0.1Mg0.8Fe2+0.2Cr1.2Fe3+0.7Ti1.5Nb0.4Si4O22
Help on Environment: Environment: In a carbonatite vein and in phlogopite-fluororichterite rocks. Cr analogue of chevkinite-(Ce), structure
Help on IMA Status: IMA Status: Approved IMA 1998 (Dana # Added)
Help on Locality: Locality: N97 mine, Ilmen Natural Reserve, southern Urals, Russia. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Vladislav O. Polyakoy (1950-1993), Russian mineralogist.
Help on Synonym: Synonym: IMA1998-029
 

Polyakovite-(Ce) Image

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  Polyakovite-(Ce)

Comments: Black, pitchy, polyakovite-(Ce) crystal showing conchoidal surfaces so typical for this mineral. Green fluororichterite overgrowth is just visible. Measured radioactivity is 146µR/h.
Location: Pit No. 97 (N97 Mine), Ilmen Natural Reserve, Ilmen Mts, Chelyabinsk Oblast', Southern Urals, Urals Region, Russia. Scale: Specimen size is 4.5x3x2.5 cm.
© Pavel M. Kartashov

Polyakovite-(Ce) Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =2.3515:1:1.938
Help on Cell Dimensions: Cell Dimensions: a = 13.397, b = 5.697, c = 11.041, Z = 2; beta = 100.53° V = 828.49 Den(Calc)= 5.03
Help on Crystal System: Crystal System: Monoclinic - Prismatic H-M Symbol (2/m) Space Group: C 2/m
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 2.715(1)(004), 3.18(0.5)(311), 2.16(0.45)(421),2.849(0.4)(020), 3.15(0.4)(312), 5.44(0.4)(002), 3.12(0.35), 3.62(0.35),
 

Physical Properties of Polyakovite-(Ce)

Help on Color: Color: Black.
Help on Density: Density: 4.75
Help on Diaphaneity: Diaphaneity: Opaque to translucent
Help on Fracture: Fracture: Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.
Help on Habit: Habit: Amorphous - No crystalline form or imitative shape.
Help on Habit: Habit: Euhedral Crystals - Occurs as well-formed crystals showing good external form.
Help on Habit: Habit: Metamict - Mineral originally crystalline, now amorphous due to radiation damage.
Help on Hardness: Hardness: 5.5-6 - Knife Blade-Orthoclase
Help on Luster: Luster: Resinous
Help on Streak: Streak: light brown
 

Optical Properties of Polyakovite-(Ce)

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.048 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= 0.101 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1855,KPDmeas= 0.1964,KC= 0.2063
Ncalc = 1.98 - 2.04
Help on Optical Data: Optical Data: Isotropic, n=1.931-1.935.
Help on RL Color: RL Color: Gray.
Help on RL Pleochroism: RL Pleochroism: None.
Help on Reflectivity Reflectivity
Standardized Intensity (100%) Reflection Spectra of Polyakovite-(Ce) in Air
λ R  ∑ R(λ) 
 480 nm   11.10   
 540 nm   10.90 
 580 nm   10.80 
 640 nm   10.50 
Calculated Relative Intensity Colors of Polyakovite-(Ce) in Air
Relative
Intensity
   0%   90% 100% 180% 270% 360% 450% 540% 630% 720% 810% 820%
R                        
 

Calculated Properties of Polyakovite-(Ce)

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=4.32 gm/cc
note: Specific Gravity of Polyakovite-(Ce) =4.75 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.02
Boson Index = 0.98
Help on Photoelectric: Photoelectric: PEPolyakovite-(Ce) = 260.59 barns/electron
U=PEPolyakovite-(Ce) x relectron=1,125.20 barns/cc.
Help on Radioactivity: Radioactivity:

GRapi = 35,843.04 (Gamma Ray American Petroleum Institute Units)
Concentration of Polyakovite-(Ce) per GRapi unit = 27.90 (PPM)

Polyakovite-(Ce) is Radioactive as defined in 49 CFR 173.403. Greater than 70 Bq / gram.

Estimated Maximum U.S. Postal Shipping Size (10 mRem/hr limit, Unshielded 10 cm box) 848.61 ±212.15 grams of pure Polyakovite-(Ce) .

Estimated Radioactivity from Polyakovite-(Ce) - weak
Specimen
Size
Weight/Volume
(Sphere)
*
Calculated
Activity
Bequerols
(Bq)
Calculated
Activity
Curies (Ci)
Estimated
Activity
GR(api)
Estimated
Exposure
(mRem**)/hr
If Held in Hand
For One Hour
1000 gm / 7.38 cm 828,037 2.24E-05 35,843.04 11.78
100 gm / 3.43 cm 82,804 2.24E-06 3,584.30 1.18
10 gm / 1.59 cm 8,280 2.24E-07 358.43 0.12
1 gm / 7.38 mm 828 2.24E-08 35.84 0.01
0.1 gm / 3.43 mm 83 2.24E-09 3.58 0.00
0.01 gm / 1.59 mm 8 2.24E-10 0.36 0.00
0.001 gm / 0.74 mm 1 2.24E-11 0.04 0.00

Weight of pure Polyakovite-(Ce) in grams (gm) and Calculated Diameter of a Sphere with a Density of 4.75 gm/cc.*
Goverment Estimate of Average Annual Exposure ( 360 mRem) **
Note: 10 microsieverts/hr = 1 mRem/hr **
Max Permissable Adult Dose 50,000 mRem/yr (hands), 15,000 mRem/yr (eyes)
Lethal Dose LD(50) Exposure 400,000 to 500,000 mRem
 

Polyakovite-(Ce) Classification

Help on  Dana Class: Dana Class: 56.02.08.07 (56)Sorosilicate Si2O7 Groups and O, OH, F. and H2O
  (56.02)with cations in [4] and/or >[4] coordination
  (56.02.08)Perierite - Chevkinite group
 
56.02.08.01 Chevkinite-(Ce) (Ce,La,Ca,Th)4(Fe,Mg)2(Ti,Fe)3Si4O22 C 2/m 2/m
 
56.02.08.02 Strontiochevkinite (Sr,REE)4Fe(Ti,Zr)2Ti2Si4O22 C 2/a 2/m
 
56.02.08.03 Perrierite-(Ce) (Ce,La,Ca)4(Fe,Mg)2(Ti,Fe)3Si4O22 C 21/a 2/m
 
56.02.08.04 Orthochevkinite* (Ce,La,Ca,Na,Th)4(Fe,Mg)2(Ti,Fe)3Si4O22 Unk Ortho
 
56.02.08.05 Rengeite! Sr4ZrTi4Si4O22 P 21/a 2/m
 
56.02.08.06 Matsubaraite! Sr4TiTi4Si4O22 P 21/a 2/m
 
56.02.08.07 Polyakovite-(Ce)! (Ce,La,Nd,Pr,Ca)4(Mg,Fe)(Cr,Fe)2(Ti,Nb)2Si4O22 C 2/m 2/m
 
56.02.08.08 Maoniupingite-(Ce)! (REE,Ca)4(Fe,Ti,Fe,[])(Ti,Fe,Fe,Nb)4Si4O22 C 2/m 2/m
 
56.02.08.09 Dingdaohengite-(Ce)! (Ce,La)4Fe(Ti,Fe,Mg,Fe)2Ti2Si4O22 P 21/a (pseudo-C 2/m) 2/m
Help on  Strunz Class: Strunz Class: 09.BE.70 09 - SILICATES (Germanates)
  09.B - Sorosilicates
  09.BE -Si2O7 groups with additional anions;
 
09.BE.70 Chevkinite-(Ce) (Ce,La,Ca,Th)4(Fe,Mg)2(Ti,Fe)3Si4O22 C 2/m 2/m
 
09.BE.70 Karnasurtite-(Ce) (Ce,La,Th)(Ti,Nb)(Al,Fe)(Si,P)2O7(OH)4•3(H2O)(?) Unk. Hex
 
09.BE.70 Perrierite-(Ce) (Ce,La,Ca)4(Fe,Mg)2(Ti,Fe)3Si4O22 C 21/a 2/m
 
09.BE.70 Strontiochevkinite (Sr,REE)4Fe(Ti,Zr)2Ti2Si4O22 C 2/a 2/m
 
09.BE.70 Rengeite! Sr4ZrTi4Si4O22 P 21/a 2/m
 
09.BE.70 Maoniupingite-(Ce)! (REE,Ca)4(Fe,Ti,Fe,[])(Ti,Fe,Fe,Nb)4Si4O22 C 2/m 2/m
 
09.BE.70 Matsubaraite! Sr4TiTi4Si4O22 P 21/a 2/m
 
09.BE.70 Polyakovite-(Ce)! (Ce,La,Nd,Pr,Ca)4(Mg,Fe)(Cr,Fe)2(Ti,Nb)2Si4O22 C 2/m 2/m
 
09.BE.70 Dingdaohengite-(Ce)! (Ce,La)4Fe(Ti,Fe,Mg,Fe)2Ti2Si4O22 P 21/a (pseudo-C 2/m) 2/m
 

Other Polyakovite-(Ce) Information

Help on References: References: NAME( AmMin, Vol 87, p 766) PHYS. PROP.(AmMin, Vol 87, p 766) OPTIC PROP.(AmMin, Vol 87, p 766)
Help on See Also: See Also: Links to other databases for Polyakovite-(Ce) :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - GeoScienceWorld
4 - Google Images
5 - Google Scholar
6 - MinDAT
7 - Mineralienatlas (Deutsch)
8 - Online Mineral Museum
9 - QUT Mineral Atlas
10 - Ruff.Info

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Print or Cut-and-Paste your Polyakovite-(Ce) Specimen Label here :

Polyakovite-(Ce)

(Ce,La,Nd,Pr,Ca)4(Mg,Fe++)(Cr,Fe+++)2(Ti,Nb)2Si4O22
Dana No: 56.02.08.07 Strunz No: 09.BE.70
Locality:

 

Notes:

 

 
   
 


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