Brittle - Uneven - Very brittle fracture producing uneven fragments.
Habit:
Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).
Hardness:
4 - Fluorite
Luster:
Adamantine
Streak:
white
Optical Properties of Wakefieldite-(La)
Gladstone-Dale:
CI calc= 0.117 (Poor) - where the CI = (1-KPDcalc/KC) KPDcalc= 0.1907,KC= 0.216 Ncalc = 2.02
Optical Data:
Uniaxial (+), w=1.9, e=1.9, bire=0.0000.
Calculated Properties of Wakefieldite-(La)
Electron Density:
Bulk Density (Electron Density)=4.18 gm/cc note: Specific Gravity of Wakefieldite-(La) =4.72 gm/cc.
Fermion Index:
Fermion Index = 0.02 Boson Index = 0.98
Photoelectric:
PEWakefieldite-(La) = 282.37 barns/electron U=PEWakefieldite-(La) x relectron=1,179.31 barns/cc.
Radioactivity:
GRapi = 51,118.05 (Gamma Ray American Petroleum Institute Units)
Concentration of Wakefieldite-(La) per GRapi unit = 19.56 (PPM)
Wakefieldite-(La) 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)
595.03 ±148.76 grams of pure Wakefieldite-(La) .
Estimated Radioactivity from Wakefieldite-(La) - 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 / 7.40 cm
1,213,165
3.28E-05
51,118.05
16.81
100 gm / 3.43 cm
121,317
3.28E-06
5,111.81
1.68
10 gm / 1.59 cm
12,132
3.28E-07
511.18
0.17
1 gm / 7.40 mm
1,213
3.28E-08
51.12
0.02
0.1 gm / 3.43 mm
121
3.28E-09
5.11
0.00
0.01 gm / 1.59 mm
12
3.28E-10
0.51
0.00
0.001 gm / 0.74 mm
1
3.28E-11
0.05
0.00
Weight of pure Wakefieldite-(La) in grams (gm) and Calculated Diameter of a Sphere with a Density of 4.72 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 ( 2.71 % Th) From Sum REE Elements (54.13 % REE)
Chemical Formula: 
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- weak