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Hellandite-(Y) Mineral Data

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General Hellandite-(Y) Information

Help on Chemical  Formula: Chemical Formula: (Ca,REE)4(Y,Ce)2(Al,[ ])2[Si4B4O22](OH)2
Help on Composition: Composition: Molecular Weight = 1,029.47 gm
   Calcium          11.68 %  Ca   16.34 % CaO
   Cerium            6.81 %  Ce    7.97 % Ce2O3
   La,Ce,Pr,Nd,Sm,  13.99 %  RE   16.32 % REE2O3
   Yttrium          12.95 %  Y    16.45 % Y2O3
   Aluminum          1.97 %  Al    3.71 % Al2O3
   Silicon          10.91 %  Si   23.35 % SiO2
   Boron             4.20 %  B    13.53 % B2O3
   Hydrogen          0.20 %  H     1.75 % H2O
   Oxygen           37.30 %  O
                   ______        ______ 
                   100.00 %       99.42 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Ca3REEY1.5Ce0.5Al0.75(Si4B4O22)(OH)2
Help on Environment: Environment: Pegmatite
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1903
Help on Locality: Locality: Kragero, Telemark, Norway. 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-(Y) + Pronunciation Say HELLANDITE-(Y)
Help on Synonym: Synonym: Hellandite
  ICSD 100145
  IMA2000-F
  PDF 25-184
 

Hellandite-(Y) Image

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  Hellandite-(Y)

Comments: Short-prismatic crystal of dark-brown hellandite-(Y) in granitic pegmatite.
Location: Tusion River Valley, Pamir Mts, Viloyati Mukhtori Gorno-Badakhshan (Viloyati Badakhshoni Kuni), Tajikistan. Scale: FOV is 2x1.7 cm.
© Pavel M. Kartashov

Hellandite-(Y) Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =4.0275:1:2.1845
Help on Cell Dimensions: Cell Dimensions: a = 18.99, b = 4.715, c = 10.3, Z = 2; beta = 111.4° V = 858.66 Den(Calc)= 3.98
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): 2.63(1), 1.89(0.6), 2.82(0.6),
 

Physical Properties of Hellandite-(Y)

Help on Cleavage: Cleavage: {001} Poor, {100} Poor
Help on Color: Color: Green yellow, Grayish black, Reddish brown, Black.
Help on Density: Density: 3.7
Help on Diaphaneity: Diaphaneity: Translucent to subtranslucent
Help on Fracture: Fracture: Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.
Help on Habit: Habit: Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).
Help on Hardness: Hardness: 5.5-6 - Knife Blade-Orthoclase
Help on Luminescence: Luminescence: Non-fluorescent.
Help on Luster: Luster: Vitreous - Greasy
 

Optical Properties of Hellandite-(Y)

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.057 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= 0.123 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1633,KPDmeas= 0.1757,KC= 0.1863
Ncalc = 1.69 - 1.74
Help on Optical Data: Optical Data: Biaxial (+), a=1.64, b=1.65, g=1.66, bire=0.0200, 2V(Calc)=88, 2V(Meas)=80.
 

Calculated Properties of Hellandite-(Y)

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=3.51 gm/cc
note: Specific Gravity of Hellandite-(Y) =3.70 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.03
Boson Index = 0.97
Help on Photoelectric: Photoelectric: PEHellandite-(Y) = 134.74 barns/electron
U=PEHellandite-(Y) x relectron= 472.90 barns/cc.
Help on Radioactivity: Radioactivity:

GRapi = 21,088.76 (Gamma Ray American Petroleum Institute Units)
Concentration of Hellandite-(Y) per GRapi unit = 47.42 (PPM)

Hellandite-(Y) is Radioactive as defined in 49 CFR 173.403. Greater than 70 Bq / gram.

Estimated Radioactivity from Hellandite-(Y) - 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 / 8.02 cm 466,887 1.26E-05 21,088.76 6.93
100 gm / 3.72 cm 46,689 1.26E-06 2,108.88 0.69
10 gm / 1.73 cm 4,669 1.26E-07 210.89 0.07
1 gm / 8.02 mm 467 1.26E-08 21.09 0.01
0.1 gm / 3.72 mm 47 1.26E-09 2.11 0.00
0.01 gm / 1.73 mm 5 1.26E-10 0.21 0.00
0.001 gm / 0.80 mm 0 1.26E-11 0.02 0.00

Weight of pure Hellandite-(Y) in grams (gm) and Calculated Diameter of a Sphere with a Density of 3.70 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 ( 1.04 % Th) From Sum REE Elements (20.79 % REE)
 

Hellandite-(Y) Classification

Help on  Dana Class: Dana Class: 54.02.02.01 (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-(Y) Information

Help on References: References: NAME( Ford32) 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 Hellandite-(Y) :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - GeoScienceWorld
5 - Google Images
6 - Google Scholar
7 - MinDAT
8 - Mineralienatlas (Deutsch)
9 - Online Mineral Museum
10 - QUT Mineral Atlas
11 - Ruff.Info
12 - Uranium Minerals

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

Hellandite-(Y)

(Ca,REE)4(Y,Ce)2(Al,[ ])2[Si4B4O22](OH)2
Dana No: 54.02.02.01 Strunz No: 09.DK.20
Locality:

 

Notes:

 

 
   
 


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