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.
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:
PEAeschynite-(Ce) = 154.95 barns/electron U=PEAeschynite-(Ce) x relectron= 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
Chemical Formula: 
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- weak