Brittle - Generally displayed by glasses and most non-metallic minerals.
Habit:
Lath - Shaped like a small, thin plaster lath, tabular (rectangular) in shape.
Habit:
Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite)
Hardness:
3.5 - Copper Penny
Luster:
Adamantine - Greasy
Streak:
yellow white
Optical Properties of Walpurgite
Gladstone-Dale:
CI meas= -0.082 (Poor) - where the CI = (1-KPDmeas/KC) CI calc= 0.036 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1423,KPDmeas= 0.1597,KC= 0.1476 Ncalc = 1.88 - 1.99
Estimated Radioactivity from Walpurgite - 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 / 6.59 cm
28,714,596
7.76E-04
1,146,367.29
376.89
100 gm / 3.06 cm
2,871,460
7.76E-05
114,636.73
37.69
10 gm / 1.42 cm
287,146
7.76E-06
11,463.67
3.77
1 gm / 6.59 mm
28,715
7.76E-07
1,146.37
0.38
0.1 gm / 3.06 mm
2,871
7.76E-08
114.64
0.04
0.01 gm / 1.42 mm
287
7.76E-09
11.46
0.00
0.001 gm / 0.66 mm
29
7.76E-10
1.15
0.00
Weight of pure Walpurgite in grams (gm) and Calculated Diameter of a Sphere with a Density of 6.68 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
Chemical Formula: 
- very strong