Mineralogy Database

Melanocerite-(Ce) Mineral Data

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General Melanocerite-(Ce) Information

Help on Chemical  Formula: Chemical Formula: (Ce,Th,Ca)5(Si,B)3O12(OH,F)•n(H2O) (?)
Help on Composition: Composition: Molecular Weight = 903.06 gm
   Calcium     4.88 %  Ca    6.83 % CaO
   Lanthanum  10.77 %  La   12.63 % La2O3
   Cerium     46.55 %  Ce   54.52 % Ce2O3
   Thorium     5.14 %  Th    5.85 % ThO2
   Silicon     6.22 %  Si   13.31 % SiO2
   Boron       1.20 %  B     3.85 % B2O3
   Hydrogen    0.28 %  H     2.49 % H2O
   Oxygen     23.92 %  O
   Fluorine    1.05 %  F     1.05 % F
                -   %   F    -0.44 % -O=F2    
             ______        ______ 
             100.00 %      100.09 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Ce3La0.7Th0.2Ca1.1Si2BO12(OH)0.5F0.5•(H2O)
Help on Environment: Environment: Alkalic rocks and their cogenetic pegmatites. Also in metamorphosed alkalic rocks.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1887
Help on Locality: Locality: Isle of Kjeo in the Langesundfiord district, southern Norway. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named from the Greek meaning "black" and the composition (Cerium).
Help on Name Pronunciation: Name Pronunciation: Melanocerite-(Ce) + Pronunciation Say MELANOCERITE-(CE)

Melanocerite-(Ce) Image

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Comments: Black, vitreous, crystalline aggregates of melanocerite-(Ce) in matrix.
Location: Cardiff Uranium mine, Wilberforce, Monmouth Township, Haliburton Co., Ontario, Canada. Scale: See Image.
© Paul M. Schumacher

Melanocerite-(Ce) Crystallography

Help on Axial Ratios: Axial Ratios: a:c = 1:0.73582
Help on Cell Dimensions: Cell Dimensions: a = 9.35, c = 6.88, Z = 2; V = 520.89 Den(Calc)= 5.76
Help on Crystal System: Crystal System: Trigonal Space Group: Unk (HEX-R)
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 2.81(1), 1.84(0.4), 3.44(0.4),

Physical Properties of Melanocerite-(Ce)

Help on Cleavage: Cleavage: None
Help on Color: Color: Brown, Black, Dark brown, Reddish brown.
Help on Density: Density: 4.13
Help on Diaphaneity: Diaphaneity: Subtransparent to opaque
Help on Fracture: Fracture: Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.
Help on Habit: Habit: Metamict - Mineral originally crystalline, now amorphous due to radiation damage.
Help on Habit: Habit: Tabular - Form dimensions are thin in one direction.
Help on Hardness: Hardness: 5-6 - Between Apatite and Orthoclase
Help on Luminescence: Luminescence: Radioactive.
Help on Luster: Luster: Resinous
Help on Streak: Streak: light brown

Optical Properties of Melanocerite-(Ce)

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.056 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= 0.243 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1259,KPDmeas= 0.1755,KC= 0.1662
Ncalc = 1.69 - 1.96
Help on Optical Data: Optical Data: Uniaxial (-), e=1.72, w=1.73, bire=0.0100.

Calculated Properties of Melanocerite-(Ce)

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=3.68 gm/cc
note: Specific Gravity of Melanocerite-(Ce) =4.13 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0055649447
Boson Index = 0.9944350553
Help on Photoelectric: Photoelectric: PEMelanocerite-(Ce) = 415.84 barns/electron
U=PEMelanocerite-(Ce) x relectron=1,528.65 barns/cc.
Help on Radioactivity: Radioactivity:

GRapi = 97,579.54 (Gamma Ray American Petroleum Institute Units)
Concentration of Melanocerite-(Ce) per GRapi unit = 10.25 (PPM)

Melanocerite-(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) 311.71 ± 77.93 grams of pure Melanocerite-(Ce) .

Estimated Radioactivity from Melanocerite-(Ce) - weak
Curies (Ci)
If Held in Hand
For One Hour
1000 gm / 7.73 cm 2,302,230 6.22E-05 97,579.54 32.08
100 gm / 3.59 cm 230,223 6.22E-06 9,757.95 3.21
10 gm / 1.67 cm 23,022 6.22E-07 975.80 0.32
1 gm / 7.73 mm 2,302 6.22E-08 97.58 0.03
0.1 gm / 3.59 mm 230 6.22E-09 9.76 0.00
0.01 gm / 1.67 mm 23 6.22E-10 0.98 0.00
0.001 gm / 0.77 mm 2 6.22E-11 0.10 0.00

Weight of pure Melanocerite-(Ce) in grams (gm) and Calculated Diameter of a Sphere with a Density of 4.13 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

Melanocerite-(Ce) Classification

Help on  Dana Class: Dana Class: (54)Nesosilicate Borosilicates and Some Beryllosilicates
  (54.02)with B in [4] coordination
  (54.02.05)Tritomite group Tritomite-(Ce) (Ce,La,Ca,Y,Th)5(Si,B)3(O,OH,F)13 P 63/m 6/m Tritomite-(Y) (Y,Ca,La,Fe)5(Si,B,Al)3(O,OH,F)13(?) P 63/m 6/m Melanocerite-(Ce) (Ce,Th,Ca)5(Si,B)3O12(OH,F)•n(H2O)(?) Unk (HEX-R) Trig
Help on  Strunz Class: Strunz Class: 09.AJ.20 09 - SILICATES (Germanates)
  09.A - Nesosilicates
  09.AJ -Nesosilicates with BO3 triangles and/or B[4], Be[4] tetrahedra,
09.AJ.20 Bakerite Ca4B4(BO4)(SiO4)3(OH)3•(H2O) P 21/c 2/m
09.AJ.20 Calcybeborosilite-(Y)! (REE,Ca)2[](B,Be)2(SiO4)2(OH,O)2 P 21/a 2/m
09.AJ.20 Calciogadolinite? CaREE(Fe)Be2Si2O10 P 21/a 2/m
09.AJ.20 Datolite CaBSiO4(OH) P 21/c 2/m
09.AJ.20 Hingganite-(Yb) (Yb,Y)2([])Be2Si2O8(OH)2 P 21/a 2/m
09.AJ.20 Homilite Ca2(Fe,Mg)B2Si2O10 P 21/a 2/m
09.AJ.20 Gadolinite-(Ce) (Ce,La,Nd,Y)2FeBe2Si2O10 P 21/c 2/m
09.AJ.20 Gadolinite-(Y) Y2FeBe2Si2O10 P 21/a 2/m
09.AJ.20 Hingganite-(Ce) (Ce,Ca)2([],Fe)Be2Si2O8[(OH),O]2 P 21/a 2/m
09.AJ.20 Hingganite-(Y) Y2([])Be2Si2O8(OH)2 P 21/a 2/m
09.AJ.20 Melanocerite-(Ce) (Ce,Th,Ca)5(Si,B)3O12(OH,F)•n(H2O)(?) Unk (HEX-R) Trig
09.AJ.20 Minasgeraisite-(Y) CaY2Be2Si2O10 P 21/a 2/m

Other Melanocerite-(Ce) Information

Help on References: References: NAME( Ford32) PHYS. PROP.(Dana8) OPTIC PROP.(Ford32)
Help on See Also: See Also: Links to other databases for Melanocerite-(Ce) :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - GeoScienceWorld
5 - Google Images
6 - Google Scholar
7 - Handbook of Mineralogy (UofA)
8 - MinDAT
9 - Mineralienatlas (Deutsch)
10 - Online Mineral Museum
11 - QUT Mineral Atlas
12 - Ruff.Info

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


(Ce,Th,Ca)5(Si,B)3O12(OH,F)•n(H2O) (?)
Dana No: Strunz No: 09.AJ.20





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