Mineralogy Database

Tristramite Mineral Data

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General Tristramite Information

Help on Chemical  Formula: Chemical Formula: (Ca,U++++,Fe+++)(PO4,SO4)•2(H2O)
Help on Composition: Composition: Molecular Weight = 232.32 gm
   Calcium     10.35 %  Ca   14.48 % CaO
   Uranium     30.74 %  U    34.87 % UO2
   Iron         2.40 %  Fe    3.44 % Fe2O3
   Phosphorus  10.00 %  P    22.91 % P2O5
   Hydrogen     1.74 %  H    15.51 % H2O
   Sulfur       3.45 %  S     8.62 % SO3
   Oxygen      41.32 %  O
              ______        ______ 
              100.00 %       99.83 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Ca0.6U0.3Fe3+0.1(PO4)0.75(SO4)0.25•2(H2O)
Help on Environment: Environment: Fractures and cavities in hydrothermal veins.
Help on IMA Status: IMA Status: Approved IMA 1983
Help on Locality: Locality: Wheal Trewavas, England. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Sir Tristram, a figure in the Arthurian legend.
Help on Name Pronunciation: Name Pronunciation: Tristramite + Pronunciation Say TRISTRAMITE
 

Tristramite Image

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  Tristramite

Comments: Reflected light, crossed polars showing a cavity with tristramite (white) infill and surrounded by intergrowth of marcasite (dark) and pitchblende (dark). (MinMag, v47:344).
Location: Wheal Trewavas Head dumps, Cornwall, UK. Scale: Scale bar = 0.1 mm.
© Mineralogical Magazine

Tristramite Crystallography

Help on Axial Ratios: Axial Ratios: a:c = 1:0.92897
Help on Cell Dimensions: Cell Dimensions: a = 6.913, c = 6.422, Z = 3; V = 265.79 Den(Calc)= 4.35
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): 2.83(1), 2.99(1), 2.14(0.5),
 

Physical Properties of Tristramite

Help on Cleavage: Cleavage: None
Help on Color: Color: Green yellow, Light yellow.
Help on Density: Density: 3.8 - 4.2, Average = 4
Help on Diaphaneity: Diaphaneity: Translucent
Help on Hardness: Hardness: 3-4 - Calcite-Fluorite
Help on Luster: Luster: Greasy (Oily)
 

Optical Properties of Tristramite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.121 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= 0.192 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1503,KPDmeas= 0.1635,KC= 0.186
Ncalc = 1.71 - 1.81
Help on Optical Data: Optical Data: Uniaxial (+), w=1.644, e=1.664, bire=0.0200.
 

Calculated Properties of Tristramite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=3.77 gm/cc
note: Specific Gravity of Tristramite =4.00 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0033222458
Boson Index = 0.9966777542
Help on Photoelectric: Photoelectric: PETristramite = 742.96 barns/electron
U=PETristramite x relectron=2,800.22 barns/cc.
Help on Radioactivity: Radioactivity:

GRapi = 2,468,740.13 (Gamma Ray American Petroleum Institute Units)
Concentration of Tristramite per GRapi unit = 405.06 (PPB)

Tristramite 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) 12.32 ± 3.08 grams of pure Tristramite .
Estimated Maximum U.S. Postal Shipping Size (10 mRem/hr limit, Unshielded 100 cm box) 1232.1 ±308.02 grams of pure Tristramite .

Estimated Radioactivity from Tristramite - 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 / 7.82 cm 55,020,742 1.49E-03 2,468,740.13 811.64
100 gm / 3.63 cm 5,502,074 1.49E-04 246,874.01 81.16
10 gm / 1.68 cm 550,207 1.49E-05 24,687.40 8.12
1 gm / 7.82 mm 55,021 1.49E-06 2,468.74 0.81
0.1 gm / 3.63 mm 5,502 1.49E-07 246.87 0.08
0.01 gm / 1.68 mm 550 1.49E-08 24.69 0.01
0.001 gm / 0.78 mm 55 1.49E-09 2.47 0.00

Weight of pure Tristramite in grams (gm) and Calculated Diameter of a Sphere with a Density of 4.00 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
 

Tristramite Classification

Help on  Dana Class: Dana Class: 40.04.07.06 (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 Tristramite Information

Help on References: References: NAME( AntBidBlaNic4) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)
Help on See Also: See Also: Links to other databases for Tristramite :
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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Tristramite

(Ca,U++++,Fe+++)(PO4,SO4)•2(H2O)
Dana No: 40.04.07.06 Strunz No: 08.CJ.45
Locality:

 

Notes:

 

 
   
 


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