Mineralogy Database

Grayite Mineral Data

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General Grayite Information

Help on Chemical  Formula: Chemical Formula: (Th,Pb,Ca)PO4•(H2O)
Help on Composition: Composition: Molecular Weight = 318.38 gm
   Calcium      1.26 %  Ca    1.76 % CaO
   Thorium     43.73 %  Th   49.76 % ThO2
   Phosphorus   9.73 %  P    22.29 % P2O5
   Hydrogen     0.63 %  H     5.66 % H2O
   Lead        19.52 %  Pb   21.03 % PbO
   Oxygen      25.13 %  O
              ______        ______ 
              100.00 %      100.50 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Th0.6Pb0.3Ca0.1(PO4)•(H2O)
Help on Environment: Environment: Lithium pegmatites.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1957
Help on Locality: Locality: Gooddays mine, Mtoko, and the Mahaka claim, Wedza, Zimbabwe. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Anton Gray, mining engineer, advisor to U. K. Atomic Energy Authority.
 

Grayite Crystallography

Help on Axial Ratios: Axial Ratios: a:c = 1:0.91936
Help on Cell Dimensions: Cell Dimensions: a = 6.957, c = 6.396, Z = 2; V = 268.09 Den(Calc)= 3.94
Help on Crystal System: Crystal System: Hexagonal - Trapezohedral H-M Symbol (6 2 2) Space Group: P 6222
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 3.04(1), 2.14(0.8), 2.82(0.8),
 

Physical Properties of Grayite

Help on Cleavage: Cleavage: None
Help on Color: Color: Light yellow, Reddish brown.
Help on Density: Density: 3.7 - 4.3, Average = 4
Help on Diaphaneity: Diaphaneity: Translucent
Help on Fracture: Fracture: Conchoidal - Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).
Help on Habit: Habit: Aggregates - Made of numerous individual crystals or clusters.
Help on Habit: Habit: Cryptocrystalline - Occurs as crystals too small to distinguish with the naked eye.
Help on Hardness: Hardness: 3-4 - Calcite-Fluorite
Help on Luster: Luster: Resinous
 

Optical Properties of Grayite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.035 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= 0.02 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1713,KPDmeas= 0.1688,KC= 0.1748
Ncalc = 1.65 - 1.75
Help on Optical Data: Optical Data: Uniaxial (?), a=1.66, b=1.69, bire=0.0300.
 

Calculated Properties of Grayite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=3.41 gm/cc
note: Specific Gravity of Grayite =3.94 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.04
Boson Index = 0.96
Help on Photoelectric: Photoelectric: PEGrayite =1,411.61 barns/electron
U=PEGrayite x relectron=4,807.49 barns/cc.
Help on Radioactivity: Radioactivity:

GRapi = 806,368.42 (Gamma Ray American Petroleum Institute Units)
Concentration of Grayite per GRapi unit =1,240.13 (PPB)

Grayite is Radioactive as defined in 49 CFR 173.403. Greater than 70 Bq / gram.

Estimated Maximum U.S. Postal Shipping Size (10 mRem/hr limit, Unshielded 10 cm box) 37.72 ± 9.43 grams of pure Grayite .
Estimated Maximum U.S. Postal Shipping Size (10 mRem/hr limit, Unshielded 100 cm box) 3772.1 ±943.01 grams of pure Grayite .

Estimated Radioactivity from Grayite - 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 / 7.86 cm 19,590,543 5.29E-04 806,368.42 265.11
100 gm / 3.65 cm 1,959,054 5.29E-05 80,636.84 26.51
10 gm / 1.69 cm 195,905 5.29E-06 8,063.68 2.65
1 gm / 7.86 mm 19,591 5.29E-07 806.37 0.27
0.1 gm / 3.65 mm 1,959 5.29E-08 80.64 0.03
0.01 gm / 1.69 mm 196 5.29E-09 8.06 0.00
0.001 gm / 0.79 mm 20 5.29E-10 0.81 0.00

Weight of pure Grayite in grams (gm) and Calculated Diameter of a Sphere with a Density of 3.94 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
 

Grayite Classification

Help on  Dana Class: Dana Class: 40.04.07.04 (40)Hydrated Phosphates, etc
  (40.04)where A+++ XO4 � x(H2O)
  (40.04.07)Rhabdophane Group
 
40.04.07.01 Rhabdophane-(Ce) (Ce,La)PO4•(H2O) P 6222 6 2 2
 
40.04.07.02 Rhabdophane-(La) (La,Ce)PO4•(H2O) P 6222 6 2 2
 
40.04.07.03 Rhabdophane-(Nd) (Nd,Ce,La)PO4•(H2O) P 6222 6 2 2
 
40.04.07.04 Grayite (Th,Pb,Ca)PO4•(H2O) P 6222 6 2 2
 
40.04.07.05 Brockite (Ca,Th,Ce)(PO4)•(H2O) P 6222 6 2 2
 
40.04.07.06 Tristramite (Ca,U,Fe)(PO4,SO4)•2(H2O) P 6222 6 2 2
Help on  Strunz Class: Strunz Class: 08.CJ.45 08 - PHOSPHATES, ARSENATES, VANADATES
  08.C - Phosphates without Additional Anions, with H2O
  08.CJ -With only large cations
 
08.CJ.45 Brockite (Ca,Th,Ce)(PO4)•(H2O) P 6222 6 2 2
 
08.CJ.45 Grayite (Th,Pb,Ca)PO4•(H2O) P 6222 6 2 2
 
08.CJ.45 Rhabdophane-(Ce) (Ce,La)PO4•(H2O) P 6222 6 2 2
 
08.CJ.45 Rhabdophane-(La) (La,Ce)PO4•(H2O) P 6222 6 2 2
 
08.CJ.45 Rhabdophane-(Nd) (Nd,Ce,La)PO4•(H2O) P 6222 6 2 2
 
08.CJ.45 Tristramite (Ca,U,Fe)(PO4,SO4)•2(H2O) P 6222 6 2 2
 

Other Grayite Information

Help on References: References: NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Dana8)
Help on See Also: See Also: Links to other databases for Grayite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - GeoScienceWorld
6 - Google Images
7 - Google Scholar
8 - Handbook of Mineralogy (MinSocAm)
9 - Handbook of Mineralogy (UofA)
10 - MinDAT
11 - Mineralienatlas (Deutsch)
12 - Online Mineral Museum
13 - QUT Mineral Atlas
14 - Ruff.Info
15 - Uranium Minerals

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Print or Cut-and-Paste your Grayite Specimen Label here :

Grayite

(Th,Pb,Ca)PO4•(H2O)
Dana No: 40.04.07.04 Strunz No: 08.CJ.45
Locality:

 

Notes:

 

 
   
 


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