Secondary mineral in the oxidized portions of rare-earth-bearing lead deposits.
IMA Status:
Approved IMA 1985
Locality:
Originally found on a museum specimen labelled as coming from Shinkolobwe; however the associated minerals indicate the specimen is more likely from the Kasompi mine, both in Katanga P
Link to MinDat.org Location Data.
Name Origin:
Named for Marcel Gysin (1891-1974), Professor of Mineralogy, University of Geneva, Geneva, Switzerland.
Name Pronunciation:
Gysinite-(Nd)
Synonym:
ICSD 30968
PDF 45-1402
Gysinite-(Nd) Crystallography
Axial Ratios:
a:b:c =0.5929:1:0.8529
Cell Dimensions:
a = 5.04, b = 8.5, c = 7.25, Z = 2; V = 310.59 Den(Calc)= 5.40
Brittle - Generally displayed by glasses and most non-metallic minerals.
Hardness:
4-4.5 - Between Fluorite and Apatite
Luster:
Vitreous - Greasy
Streak:
light pink
Optical Properties of Gysinite-(Nd)
Gladstone-Dale:
CI meas= -0.034 (Excellent) - where the CI = (1-KPDmeas/KC) CI calc= 0.077 (Fair) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1475,KPDmeas= 0.1653,KC= 0.1599 Ncalc = 1.77 - 1.86
Bulk Density (Electron Density)=4.20 gm/cc note: Specific Gravity of Gysinite-(Nd) =4.82 gm/cc.
Fermion Index:
Fermion Index = 0.13 Boson Index = 0.87
Photoelectric:
PEGysinite-(Nd) = 884.77 barns/electron U=PEGysinite-(Nd) x relectron=3,718.83 barns/cc.
Radioactivity:
GRapi = 26,314.20 (Gamma Ray American Petroleum Institute Units)
Concentration of Gysinite-(Nd) per GRapi unit = 38.00 (PPM)
Gysinite-(Nd) is Radioactive as defined in 49 CFR 173.403. Greater than 70 Bq / gram.
Estimated Radioactivity from Gysinite-(Nd) - 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 / 7.34 cm
633,697
1.71E-05
26,314.20
8.65
100 gm / 3.41 cm
63,370
1.71E-06
2,631.42
0.87
10 gm / 1.58 cm
6,337
1.71E-07
263.14
0.09
1 gm / 7.34 mm
634
1.71E-08
26.31
0.01
0.1 gm / 3.41 mm
63
1.71E-09
2.63
0.00
0.01 gm / 1.58 mm
6
1.71E-10
0.26
0.00
0.001 gm / 0.73 mm
1
1.71E-11
0.03
0.00
Weight of pure Gysinite-(Nd) in grams (gm) and Calculated Diameter of a Sphere with a Density of 4.82 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 ( 1.41 % Th) From Sum REE Elements (28.29 % REE)
Chemical Formula: 
- weak