Brittle - Uneven - Very brittle fracture producing uneven fragments.
Habit:
Encrustations - Forms crust-like aggregates on matrix.
Habit:
Massive - Granular - Common texture observed in granite and other igneous rock.
Hardness:
2 - Gypsum
Luster:
Vitreous (Glassy)
Streak:
white
Optical Properties of Niter
Gladstone-Dale:
CI meas= 0.038 (Excellent) - where the CI = (1-KPDmeas/KC) CI calc= 0.036 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2127,KPDmeas= 0.2122,KC= 0.2206 Ncalc = 1.46 - 1.47
Optical Data:
Biaxial (-), a=1.332, b=1.504, g=1.504, bire=0.1720, 2V(Calc)=0, 2V(Meas)=7. Dispersion weak, r < v.
Calculated Properties of Niter
Electron Density:
Bulk Density (Electron Density)=2.08 gm/cc note: Specific Gravity of Niter =2.10 gm/cc.
Fermion Index:
Fermion Index = 0.13 Boson Index = 0.87
Photoelectric:
PENiter = 4.07 barns/electron U=PENiter x relectron= 8.44 barns/cc.
Radioactivity:
GRapi = 551.91 (Gamma Ray American Petroleum Institute Units)
Concentration of Niter per GRapi unit =1,811.89 (PPM)
Estimated Radioactivity from Niter - 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 / 9.69 cm
11,718
3.17E-07
551.91
0.18
100 gm / 4.50 cm
1,172
3.17E-08
55.19
0.02
10 gm / 2.09 cm
117
3.17E-09
5.52
0.00
1 gm / 9.69 mm
12
3.17E-10
0.55
0.00
0.1 gm / 4.50 mm
1
3.17E-11
0.06
0.00
0.01 gm / 2.09 mm
0
3.17E-12
0.01
0.00
0.001 gm / 0.97 mm
0
3.17E-13
0.00
0.00
Weight of pure Niter in grams (gm) and Calculated Diameter of a Sphere with a Density of 2.10 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: 
- mild