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Hellandite-(Ce) Mineral Data

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General Hellandite-(Ce) Information

Help on Chemical  Formula: Chemical Formula: (Ca3REE)4Ce2Al[ ]2[Si4 B4O22](OH)2
Help on Composition: Composition: Molecular Weight = 1,114.02 gm
   Calcium          10.79 %  Ca   15.10 % CaO
   Cerium           25.15 %  Ce   29.46 % Ce2O3
   La,Ce,Pr,Nd,Sm,  12.93 %  RE   15.08 % REE2O3
   Aluminum          2.42 %  Al    4.58 % Al2O3
   Silicon          10.08 %  Si   21.57 % SiO2
   Boron             3.88 %  B    12.50 % B2O3
   Hydrogen          0.14 %  H     1.21 % H2O
   Oxygen           33.75 %  O
   Fluorine          0.85 %  F     0.85 % F
                      -   %   F    -0.36 % -O=F2    
                   ______        ______ 
                   100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Ca3REECe2AlSi4B4O22(OH)1.5F0.5
Help on Environment: Environment: Occurs in miarolitic cavities in a volcanic ejectum within an explosive breccia. (hellandite group; structure)
Help on IMA Status: IMA Status: Approved IMA 2001 (Dana # Added)
Help on Locality: Locality: Pyroclastic flow unit (ignibrite "C") of the Vico volcanic complex near Capranica (Viterbo Province), north of Rome, Italy. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Amund Theodor Helland (1846-1918), geologist of Oslo, Norway.
Help on Name Pronunciation: Name Pronunciation: Hellandite-(Ce) + Pronunciation Say HELLANDITE-(CE)
Help on Synonym: Synonym: IMA2000-F
 

Hellandite-(Ce) Image

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  Hellandite-(Ce)

Comments: Pale yellow platy hellandite-(Ce) crystals in a vug.
Location: Campo Pefella, near Capranica, Viterbo, Latium, Italy. Scale: See Image.
© Rruff Database

Hellandite-(Ce) Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =4.0185:1:2.1683
Help on Cell Dimensions: Cell Dimensions: a = 19.068, b = 4.745, c = 10.289, Z = 1; beta = 111.18° V = 868.04 Den(Calc)= 2.13
Help on Crystal System: Crystal System: Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 2/a
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 2.652(1), 2.635(0.73), 2.855(0.56),3.238(0.5), 1.905(0.49), 1.901(0.41), 2.916(0.35),
 

Physical Properties of Hellandite-(Ce)

Help on Color: Color: Pale brown, Light green.
Help on Diaphaneity: Diaphaneity: Transparent
Help on Habit: Habit: Euhedral Crystals - Occurs as well-formed crystals showing good external form.
Help on Habit: Habit: Microscopic Crystals - Crystals visible only with microscopes.
Help on Hardness: Hardness: 5.5-6 - Knife Blade-Orthoclase
Help on Luster: Luster: Vitreous (Glassy)
 

Optical Properties of Hellandite-(Ce)

Help on Gladstone-Dale: Gladstone-Dale: CI calc= -0.815 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.3258,KC= 0.1795
Ncalc = 1.38
Help on Optical Data: Optical Data: Biaxial (-), a=1.68, b=1.694, g=1.708, bire=0.0280
 

Calculated Properties of Hellandite-(Ce)

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=1.99 gm/cc
note: Specific Gravity of Hellandite-(Ce) =2.13 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.03
Boson Index = 0.97
Help on Photoelectric: Photoelectric: PEHellandite-(Ce) = 204.79 barns/electron
U=PEHellandite-(Ce) x relectron= 407.21 barns/cc.
Help on Radioactivity: Radioactivity:

GRapi = 37,966.68 (Gamma Ray American Petroleum Institute Units)
Concentration of Hellandite-(Ce) per GRapi unit = 26.34 (PPM)

Hellandite-(Ce) 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) 801.14 ±200.29 grams of pure Hellandite-(Ce) .

Estimated Radioactivity from Hellandite-(Ce) - 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 / 9.64 cm 854,050 2.31E-05 37,966.68 12.48
100 gm / 4.48 cm 85,405 2.31E-06 3,796.67 1.25
10 gm / 2.08 cm 8,541 2.31E-07 379.67 0.12
1 gm / 9.64 mm 854 2.31E-08 37.97 0.01
0.1 gm / 4.48 mm 85 2.31E-09 3.80 0.00
0.01 gm / 2.08 mm 9 2.31E-10 0.38 0.00
0.001 gm / 0.96 mm 1 2.31E-11 0.04 0.00

Weight of pure Hellandite-(Ce) in grams (gm) and Calculated Diameter of a Sphere with a Density of 2.13 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 ( 1.90 % Th) From Sum REE Elements (38.08 % REE)
 

Hellandite-(Ce) Classification

Help on  Dana Class: Dana Class: 54.02.02.04 (54)Nesosilicate Borosilicates and Some Beryllosilicates
  (54.02)with B in [4] coordination
  (54.02.02)Hellandite group
 
54.02.02.01 Hellandite-(Y) (Ca,REE)4(Y,Ce)2(Al,[])2[Si4B4O22](OH)2 P 2/a 2/m
 
54.02.02.02 Tadzhikite-(Y)! Ca4(Y,Ce)2(Ti,Al,Fe,[])2[Si4B4O22](OH)2 P 2/a 2/m
 
54.02.02.03 Tadzhikite-(Ce) Ca4(Ce,Y)2(Ti,Al,Fe,[])2[Si4B4O22](OH)2 P 2/a 2/m
 
54.02.02.04 Hellandite-(Ce)! (Ca3REE)4Ce2Al[]2[Si4B4O22](OH)2 P 2/a 2/m
 
54.02.02.05 Mottanaite-(Ce)! Ca4(Ce,Ca)2AlBe2[Si4B4O22]O2 P 2/a 2/m
 
54.02.02.06 Ciprianiite! Ca4[(Th,U)(REE)]2(Al,[])2[Si4B4O22](OH,F)2 P 2/a 2/m
 
54.02.02.07 Piergorite-(Ce)! Ca8Ce2(Al0.5Fe0.5)([],Li,Be)2Si6B8O36(OH,F)2 P 2/a 2/m
Help on  Strunz Class: Strunz Class: 09.DK.20 09 - SILICATES (Germanates)
  09.D - Inosilicates* Structural terminology according to Liebau (1985)
  09.DK -Inosilicates with 5-periodic single chains
 
09.DK.20 Hellandite-(Y) (Ca,REE)4(Y,Ce)2(Al,[])2[Si4B4O22](OH)2 P 2/a 2/m
 
09.DK.20 Tadzhikite-(Ce) Ca4(Ce,Y)2(Ti,Al,Fe,[])2[Si4B4O22](OH)2 P 2/a 2/m
 
09.DK.20 Tadzhikite-(Y)! Ca4(Y,Ce)2(Ti,Al,Fe,[])2[Si4B4O22](OH)2 P 2/a 2/m
 
09.DK.20 Ciprianiite! Ca4[(Th,U)(REE)]2(Al,[])2[Si4B4O22](OH,F)2 P 2/a 2/m
 
09.DK.20 Hellandite-(Ce)! (Ca3REE)4Ce2Al[]2[Si4B4O22](OH)2 P 2/a 2/m
 
09.DK.20 Mottanaite-(Ce)! Ca4(Ce,Ca)2AlBe2[Si4B4O22]O2 P 2/a 2/m
 

Other Hellandite-(Ce) Information

Help on References: References: NAME( AmMin, Vol 84, p 913) PHYS. PROP.(AmMin, Vol 84, p 913) OPTIC PROP.(AmMin, Vol 84, p 913)
Help on See Also: See Also: Links to other databases for Hellandite-(Ce) :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - GeoScienceWorld
4 - Google Images
5 - Google Scholar
6 - MinDAT
7 - Mineralienatlas (Deutsch)
8 - Online Mineral Museum
9 - QUT Mineral Atlas
10 - Ruff.Info
11 - Uranium Minerals

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Print or Cut-and-Paste your Hellandite-(Ce) Specimen Label here :

Hellandite-(Ce)

(Ca3REE)4Ce2Al[ ]2[Si4 B4O22](OH)2
Dana No: 54.02.02.04 Strunz No: 09.DK.20
Locality:

 

Notes:

 

 
   
 


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