Crystalline - Fine - Occurs as well-formed fine sized crystals.
Habit:
Pyramidal - Crystals are shaped like pyramids.
Hardness:
4-4.5 - Between Fluorite and Apatite
Luster:
Vitreous (Glassy)
Streak:
white
Optical Properties of Ancylite-(La)
Gladstone-Dale:
CI meas= -0.002 (Superior) - where the CI = (1-KPDmeas/KC) CI calc= 0.028 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1699,KPDmeas= 0.1752,KC= 0.1749 Ncalc = 1.68 - 1.7
Optical Data:
Biaxial (+), a=1.64, b=1.668, g=1.731, bire=0.0910, 2V(Calc)=70, 2V(Meas)=70. Dispersion r < v moderate.
Calculated Properties of Ancylite-(La)
Electron Density:
Bulk Density (Electron Density)=3.54 gm/cc note: Specific Gravity of Ancylite-(La) =3.88 gm/cc.
Fermion Index:
Fermion Index = 0.01 Boson Index = 0.99
Photoelectric:
PEAncylite-(La) = 201.59 barns/electron U=PEAncylite-(La) x relectron= 713.81 barns/cc.
Radioactivity:
GRapi = 35,486.80 (Gamma Ray American Petroleum Institute Units)
Concentration of Ancylite-(La) per GRapi unit = 28.18 (PPM)
Ancylite-(La) is Radioactive as defined in 49 CFR 173.403. Greater than 70 Bq / gram.
Estimated Exposure (mRem**)/hr If Held in Hand For One Hour
1000 gm / 7.90 cm
816,578
2.21E-05
35,486.80
11.67
100 gm / 3.66 cm
81,658
2.21E-06
3,548.68
1.17
10 gm / 1.70 cm
8,166
2.21E-07
354.87
0.12
1 gm / 7.90 mm
817
2.21E-08
35.49
0.01
0.1 gm / 3.66 mm
82
2.21E-09
3.55
0.00
0.01 gm / 1.70 mm
8
2.21E-10
0.35
0.00
0.001 gm / 0.79 mm
1
2.21E-11
0.04
0.00
Weight of pure Ancylite-(La) in grams (gm) and Calculated Diameter of a Sphere with a Density of 3.88 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 ( 1.82 % Th) From Sum REE Elements (36.45 % REE)
Chemical Formula: 
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- weak