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Physical Properties of Tanteuxenite-(Y)
Cleavage:
{???} Indistinct
Color:
Brownish black.
Density:
5.4 - 5.9, Average = 5.65
Diaphaneity:
Subtranslucent to Opaque
Fracture:
Sub Conchoidal - Fractures developed in brittle materials characterized by semi-curving surfaces.
Habit:
Indistinct - Crystals or grains are unremarkable or poorly formed. Anhedral to subhedral crystals.
Habit:
Metamict - Mineral originally crystalline, now amorphous due to radiation damage.
Habit:
Tabular - Form dimensions are thin in one direction.
Hardness:
5-6 - Between Apatite and Orthoclase
Luster:
Resinous
Streak:
brownish gray
Optical Properties of Tanteuxenite-(Y)
Optical Data:
NCalc= 2.04 - from Gladstone-Dale relationship (KC = 0.1808) where Ncalc=Dcalc*KC+1 NCalc= 2.02 - from Gladstone-Dale relationship (KC = 0.1808) where Ncalc=Dmeas*KC+1
Calculated Properties of Tanteuxenite-(Y)
Electron Density:
Bulk Density (Electron Density)=4.99 gm/cc note: Specific Gravity of Tanteuxenite-(Y) =5.75 gm/cc.
Fermion Index:
Fermion Index = 0.0027568138 Boson Index = 0.9972431862
Photoelectric:
PETanteuxenite-(Y) = 671.48 barns/electron U=PETanteuxenite-(Y) x relectron=3,350.09 barns/cc.
Radioactivity:
GRapi = 2,697.01 (Gamma Ray American Petroleum Institute Units)
Concentration of Tanteuxenite-(Y) per GRapi unit = 370.78 (PPM)
Estimated Radioactivity from Tanteuxenite-(Y) - mild
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 / 6.93 cm
65,275
1.76E-06
2,697.01
0.89
100 gm / 3.21 cm
6,528
1.76E-07
269.70
0.09
10 gm / 1.49 cm
653
1.76E-08
26.97
0.01
1 gm / 6.93 mm
65
1.76E-09
2.70
0.00
0.1 gm / 3.21 mm
7
1.76E-10
0.27
0.00
0.01 gm / 1.49 mm
1
1.76E-11
0.03
0.00
0.001 gm / 0.69 mm
0
1.76E-12
0.00
0.00
Weight of pure Tanteuxenite-(Y) in grams (gm) and Calculated Diameter of a Sphere with a Density of 5.75 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
Estimated Thorium Activity ( 0.15 % Th) From Sum REE Elements ( 2.91 % REE)
Tanteuxenite-(Y) Classification
Dana Class:
08.03.08.03(08)Multiple Oxides with Nb, Ta, and Ti
Chemical Formula: 
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- mild