Vishnevye Gory, Ural Mountains, Russia. Link to MinDat.org Location Data.
Name Origin:
Named from the composition and the Greek for "shame," in allusion to the inability of chemists, at the time of its discovery, to separate some of its constituents.
Synonym:
Aeschynite-(Ce)
Niobo-aeschynite-(Ce) - Renamed Nioboaeschynite-(Ce) by Mineralogical Record, v39 (2008), p131
Metamict - Mineral originally crystalline, now amorphous due to radiation damage.
Hardness:
5.3-5.6
Luster:
Resinous
Optical Properties of Nioboaeschynite-(Ce)
Gladstone-Dale:
CI meas= -0.011 (Superior) - where the CI = (1-KPDmeas/KC) CI calc= 0.053 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2342,KPDmeas= 0.25,KC= 0.2474 Ncalc = 2.25 - 2.33
Optical Data:
Isotropic, n=2.26.
Calculated Properties of Nioboaeschynite-(Ce)
Electron Density:
Bulk Density (Electron Density)=4.58 gm/cc note: Specific Gravity of Nioboaeschynite-(Ce) =5.04 gm/cc.
Fermion Index:
Fermion Index = 0.0043796255 Boson Index = 0.9956203745
Photoelectric:
PENioboaeschynite-(Ce) = 185.97 barns/electron U=PENioboaeschynite-(Ce) x relectron= 851.74 barns/cc.
Radioactivity:
GRapi = 22,164.84 (Gamma Ray American Petroleum Institute Units)
Concentration of Nioboaeschynite-(Ce) per GRapi unit = 45.12 (PPM)
Nioboaeschynite-(Ce) is Radioactive as defined in 49 CFR 173.403. Greater than 70 Bq / gram.
Estimated Radioactivity from Nioboaeschynite-(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 / 7.24 cm
512,207
1.38E-05
22,164.84
7.29
100 gm / 3.36 cm
51,221
1.38E-06
2,216.48
0.73
10 gm / 1.56 cm
5,122
1.38E-07
221.65
0.07
1 gm / 7.24 mm
512
1.38E-08
22.16
0.01
0.1 gm / 3.36 mm
51
1.38E-09
2.22
0.00
0.01 gm / 1.56 mm
5
1.38E-10
0.22
0.00
0.001 gm / 0.72 mm
1
1.38E-11
0.02
0.00
Weight of pure Nioboaeschynite-(Ce) in grams (gm) and Calculated Diameter of a Sphere with a Density of 5.04 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 ( 1.14 % Th) From Sum REE Elements (22.87 % REE)
Nioboaeschynite-(Ce) Classification
Dana Class:
08.03.06.02(08)Multiple Oxides with Nb, Ta, and Ti