Aeschynite-(Ce) Mineral Data

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General Aeschynite-(Ce) Information

Chemical Formula:

(Ce,Ca,Fe)(Ti,Nb)2(O,OH)6

Composition:

Molecular Weight = 305.70 gm

Calcium 3.93 % Ca 5.50 % CaO

Cerium 27.50 % Ce 32.21 % Ce₂O₃

Titanium 27.41 % Ti 45.73 % TiO₂

Niobium 7.60 % Nb 10.87 % Nb₂O₅

Iron 1.83 % Fe 2.35 % FeO

Hydrogen 0.33 % H 2.95 % H₂O

Oxygen 31.40 % O

______ ______

100.00 % 99.61 % = TOTAL OXIDE

Empirical Formula:

Ce_0.6Ca_0.3Fe²⁺_0.1Ti_1.75Nb_0.25O₅(OH)

Environment:

Nepheline syenite rocks.

IMA Status:

Valid Species (Pre-IMA) 1828

Locality:

Russia, Chelyabinsk, Il'men Mountians. Link to MinDat.org Location Data.

Name Origin:

Named for its composition and from the Greek for "shame," in allusion to the inability of chemists, at the time of its discovery, to separate some of its constituents.

Name Pronunciation:

Aeschynite-(Ce) + Pronunciation

Synonym:

Eschynite

ICSD 20600

PDF 15-864

Aeschynite-(Ce) Image

Images:

Aeschynite-(Ce)

Comments: Prismatic crystals of Aeschynite-(Ce). Crystals were mined in 1911-1912 during works of Alexandr E. Fersman's Radium Expedition on the mine. Measured radioactivity is 183 µR/h.
Location: Blyumovskaya Pit (Blum Pit; Pit No. 50), Ilmen Natural Reserve, Ilmen Mts, Chelyabinsk Oblast', Southern Urals, Urals Region, Russia. Scale: Largest crystal size is 28x16x8 mm.
© Pavel M. Kartashov

Aeschynite-(Ce) Crystallography

Axial Ratios:

a:b:c =0.6882:1:0.494

Cell Dimensions:

a = 7.55, b = 10.97, c = 5.42, Z = 4; V = 448.90 Den(Calc)= 4.52

Crystal System:

Orthorhombic - DipyramidalH-M Symbol (2/m 2/m 2/m) Space Group: Pmnb

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 2.975(1), 3.024(0.8), 3.106(0.35),

Crystal Structure:

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Aleksandrov V B , Doklady Akademii Nauk SSSR , 142 (1962) p.181-184, The crystal structure of aeschynite

Physical Properties of Aeschynite-(Ce)

Cleavage:

None

Color:

Brown, Brownish black, Yellow, Black.

Density:

5.19

Diaphaneity:

Transparent to translucent

Fracture:

Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.

Habit:

Acicular - Occurs as needle-like crystals.

Habit:

Massive - Uniformly indistinguishable crystals forming large masses.

Hardness:

5-6 - Between Apatite and Orthoclase

Luminescence:

Non-fluorescent.

Luster:

Adamantine - Resinous

Streak:

brownish black

Optical Properties of Aeschynite-(Ce)

Gladstone-Dale:

CI meas= 0.137 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= 0.009 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2788,KPDmeas= 0.2428,KC= 0.2812
Ncalc = 2.27 - 2.46

Optical Data:

Isotropic, n=2.26.

Calculated Properties of Aeschynite-(Ce)

Electron Density:

Bulk Density (Electron Density)=4.17 gm/cc
note: Specific Gravity of Aeschynite-(Ce) =4.52 gm/cc.

Fermion Index:

Fermion Index = 0.03
Boson Index = 0.97

Photoelectric:

PE_{Aeschynite-(Ce)}= 154.95 barns/electron
U=PE_{Aeschynite-(Ce)} x r_electron= 646.77 barns/cc.

Radioactivity:

GRapi = 27,088.83 (Gamma Ray American Petroleum Institute Units)
Concentration of Aeschynite-(Ce) per GRapi unit = 36.92 (PPM)

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

**Estimated Radioactivity from Aeschynite-(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 / 7.50 cm	616,015	1.66E-05	27,088.83	8.91
100 gm / 3.48 cm	61,602	1.66E-06	2,708.88	0.89
10 gm / 1.62 cm	6,160	1.66E-07	270.89	0.09
1 gm / 7.50 mm	616	1.66E-08	27.09	0.01
0.1 gm / 3.48 mm	62	1.66E-09	2.71	0.00
0.01 gm / 1.62 mm	6	1.66E-10	0.27	0.00
0.001 gm / 0.75 mm	1	1.66E-11	0.03	0.00

Weight of pure Aeschynite-(Ce) in grams (gm) and Calculated Diameter of a Sphere with a Density of 4.52 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
Estimated Thorium Activity ( 1.38 % Th) From Sum REE Elements (27.50 % REE)

Aeschynite-(Ce) Classification

Dana Class:

08.03.06.01 (08)Multiple Oxides with Nb, Ta, and Ti

(08.03)where A (B2O6)

(08.03.06)Aeschynite group

08.03.06.01 Aeschynite-(Ce) (Ce,Ca,Fe)(Ti,Nb)2(O,OH)6 Pmnb 2/m 2/m 2/m

08.03.06.02 Nioboaeschynite-(Ce) (Ce,Ca)(Nb,Ti)2(O,OH)6 Pbnm 2/m 2/m 2/m

08.03.06.03 Aeschynite-(Y) (Y,Ca,Fe)(Ti,Nb)2(O,OH)6 Pbnm 2/m 2/m 2/m

08.03.06.04 Tantalaeschynite-(Y) (Y,Ce,Ca)(Ta,Ti,Nb)2O6 Pbnm 2/m 2/m 2/m

08.03.06.05 Aeschynite-(Nd) (Nd,Ce)(Ti,Nb)2(O,OH)6 Pmnb ? 2/m 2/m 2/m

08.03.06.06 Nioboaeschynite-(Nd)! (Nd,Ce)(Nb,Ti)2(O,OH)6 Pbnm 2/m 2/m 2/m

08.03.06.07 Nioboaeschynite-(Y)! [(Y,REE),Ca,Th,Fe](Nb,Ti,Ta)2(O,OH)6 Pbnm 2/m 2/m 2/m

Strunz Class:

04.DF.05 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate

04.D - Metal:Oxygen = 1:2 and similar

04.DF -With large (± medium-sized) cations; dimers and trimers of edge-sharing octahedra

04.DF.05 Aeschynite-(Ce) (Ce,Ca,Fe)(Ti,Nb)2(O,OH)6 Pmnb 2/m 2/m 2/m

04.DF.05 Aeschynite-(Nd) (Nd,Ce)(Ti,Nb)2(O,OH)6 Pmnb ? 2/m 2/m 2/m

04.DF.05 Aeschynite-(Y) (Y,Ca,Fe)(Ti,Nb)2(O,OH)6 Pbnm 2/m 2/m 2/m

04.DF.05 Nioboaeschynite-(Ce) (Ce,Ca)(Nb,Ti)2(O,OH)6 Pbnm 2/m 2/m 2/m

04.DF.05 Nioboaeschynite-(Nd)! (Nd,Ce)(Nb,Ti)2(O,OH)6 Pbnm 2/m 2/m 2/m

04.DF.05 Rynersonite Ca(Ta,Nb)2O6 Pmnb 2/m 2/m 2/m

04.DF.05 Tantalaeschynite-(Y) (Y,Ce,Ca)(Ta,Ti,Nb)2O6 Pbnm 2/m 2/m 2/m

04.DF.05 Vigezzite (Ca,Ce)(Nb,Ta,Ti)2O6 Pmnb 2/m 2/m 2/m

04.DF.05 Nioboaeschynite-(Y)! [(Y,REE),Ca,Th,Fe](Nb,Ti,Ta)2(O,OH)6 Pbnm 2/m 2/m 2/m

Other Aeschynite-(Ce) Information

References:

NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Aeschynite-(Ce) :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - Google Images
6 - Google Scholar
7 - Handbook of Mineralogy (UofA)
8 - MinDAT
9 - MinMax(Deutsch)
10 - MinMax(English)
11 - Mineralienatlas (Deutsch)
12 - QUT Mineral Atlas
13 - Ruff.Info
14 - Uranium Minerals
15 - WWW-MINCRYST

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

Aeschynite-(Ce)

(Ce,Ca,Fe)(Ti,Nb)2(O,OH)6
Dana No: 08.03.06.01 Strunz No: 04.DF.05
Locality:

Notes: