Brownish yellow, Brownish black, Yellow, Dark brown, Orange.
Density:
4 - 6.7, Average = 5.35
Diaphaneity:
Subtransparent to subtranslucent
Fracture:
Conchoidal - Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).
Habit:
Granular - Generally occurs as anhedral to subhedral crystals in matrix.
Habit:
Massive - Granular - Common texture observed in granite and other igneous rock.
Habit:
Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).
Hardness:
5 - Apatite
Luminescence:
Non-fluorescent.
Luster:
Resinous
Magnetism:
Nonmagnetic
Streak:
light brown
Optical Properties of Thorite
Dichroism (e):
none.
Dichroism (w):
none.
Gladstone-Dale:
CI meas= 0.136 (Poor) - where the CI = (1-KPDmeas/KC) CI calc= 0.315 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1196,KPDmeas= 0.1509,KC= 0.1746 Ncalc = 1.7 - 2.18
Estimated Radioactivity from Thorite - very strong
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 / 7.09 cm
32,072,283
8.67E-04
1,281,657.69
421.37
100 gm / 3.29 cm
3,207,228
8.67E-05
128,165.77
42.14
10 gm / 1.53 cm
320,723
8.67E-06
12,816.58
4.21
1 gm / 7.09 mm
32,072
8.67E-07
1,281.66
0.42
0.1 gm / 3.29 mm
3,207
8.67E-08
128.17
0.04
0.01 gm / 1.53 mm
321
8.67E-09
12.82
0.00
0.001 gm / 0.71 mm
32
8.67E-10
1.28
0.00
Weight of pure Thorite in grams (gm) and Calculated Diameter of a Sphere with a Density of 5.35 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
Thorite Classification
Dana Class:
51.05.02.03(51)Nesosilicate Insular SiO4 Groups Only
Chemical Formula: 
- very strong