Orthochevkinite Mineral Data

General Orthochevkinite Information

Chemical Formula:

(Ce,La,Ca,Na,Th)4(Fe++,Mg)2(Ti,Fe+++)3Si4O22

Composition:

Molecular Weight = 1,170.75 gm

Sodium 0.79 % Na 1.06 % Na₂O

Calcium 2.05 % Ca 2.87 % CaO

Lanthanum 14.24 % La 16.70 % La₂O₃

Cerium 14.36 % Ce 16.82 % Ce₂O₃

Thorium 7.93 % Th 9.02 % ThO₂

Magnesium 1.04 % Mg 1.72 % MgO

Titanium 9.20 % Ti 15.35 % TiO₂

Iron 10.73 % Fe 9.21 % FeO / 5.12 % Fe₂O₃

Silicon 9.60 % Si 20.53 % SiO₂

Oxygen 30.07 % O

______ ______

100.00 % 98.39 % = TOTAL OXIDE

Empirical Formula:

Ce_1.2La_1.2Ca_0.6Na_0.4Th_0.4Fe²⁺_1.5Mg_0.5Ti_2.25Fe³⁺_0.75Si₄O₂₂

Environment:

Alkaline syenite pegmatites. An incompletely characterized material. Physical properties by analogy with chevkinite.

IMA Status:

Not Approved IMA 1920

Locality:

Ifazina-Itorendrika Link to MinDat.org Location Data.

Name Origin:

Named as a possible orthorhombic form of chevkinite.

Orthochevkinite Crystallography

Axial Ratios:

a:b:c =2.3448:1:3.7931

Cell Dimensions:

a = 13.6, b = 5.8, c = 22, Z = 4; V = 1,735.36 Den(Calc)= 4.48

Crystal System:

Orthorhombic Space Group: Unk

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 4.15(1), 2.7(0.7), 3.78(0.7),1.69(0.5), 1.49(0.4), 2.53(0.4), 2.88(0.4),

Physical Properties of Orthochevkinite

Cleavage:

None

Color:

Brown.

Habit:

Metamict - Mineral originally crystalline, now amorphous due to radiation damage.

Hardness:

5.5 - Knife Blade

Luster:

Resinous - Greasy

Streak:

black

Optical Properties of Orthochevkinite

Optical Data:

NCalc= 1.95 - from Gladstone-Dale relationship (KC = 0.212) where Ncalc=Dcalc*KC+1

Calculated Properties of Orthochevkinite

Electron Density:

Bulk Density (Electron Density)=4.11 gm/cc
note: Specific Gravity of Orthochevkinite =4.48 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_{Orthochevkinite}= 326.86 barns/electron
U=PE_{Orthochevkinite} x r_electron=1,341.82 barns/cc.

Radioactivity:

GRapi = 154,977.55 (Gamma Ray American Petroleum Institute Units)
Concentration of Orthochevkinite per GRapi unit = 6.45 (PPM)

Orthochevkinite 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) 196.26 ± 49.07 grams of pure Orthochevkinite .

**Estimated Radioactivity from Orthochevkinite** - 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 / 7.53 cm	3,551,676	9.60E-05	154,977.55	50.95
100 gm / 3.49 cm	355,168	9.60E-06	15,497.76	5.10
10 gm / 1.62 cm	35,517	9.60E-07	1,549.78	0.51
1 gm / 7.53 mm	3,552	9.60E-08	154.98	0.05
0.1 gm / 3.49 mm	355	9.60E-09	15.50	0.01
0.01 gm / 1.62 mm	36	9.60E-10	1.55	0.00
0.001 gm / 0.75 mm	4	9.60E-11	0.15	0.00

Weight of pure Orthochevkinite in grams (gm) and Calculated Diameter of a Sphere with a Density of 4.48 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

Orthochevkinite Classification

Dana Class:

56.02.08.04 (56)Sorosilicate Si2O7 Groups and O, OH, F. and H2O

(56.02)with cations in [4] and/or >[4] coordination

(56.02.08)Perierite - Chevkinite group

56.02.08.01 Chevkinite-(Ce) (Ce,La,Ca,Th)4(Fe,Mg)2(Ti,Fe)3Si4O22 C 2/m 2/m

56.02.08.02 Strontiochevkinite (Sr,REE)4Fe(Ti,Zr)2Ti2Si4O22 C 2/a 2/m

56.02.08.03 Perrierite-(Ce) (Ce,La,Ca)4(Fe,Mg)2(Ti,Fe)3Si4O22 C 21/a 2/m

56.02.08.04 Orthochevkinite* (Ce,La,Ca,Na,Th)4(Fe,Mg)2(Ti,Fe)3Si4O22 Unk Ortho

56.02.08.05 Rengeite! Sr4ZrTi4Si4O22 P 2₁/a 2/m

56.02.08.06 Matsubaraite! Sr4TiTi4Si4O22 P 2₁/a 2/m

56.02.08.07 Polyakovite-(Ce)! (Ce,La,Nd,Pr,Ca)4(Mg,Fe)(Cr,Fe)2(Ti,Nb)2Si4O22 C 2/m 2/m

56.02.08.08 Maoniupingite-(Ce)! (REE,Ca)4(Fe,Ti,Fe,[])(Ti,Fe,Fe,Nb)4Si4O22 C 2/m 2/m

56.02.08.09 Dingdaohengite-(Ce)! (Ce,La)4Fe(Ti,Fe,Mg,Fe)2Ti2Si4O22 P 2₁/a (pseudo-C 2/m) 2/m

Strunz Class:

09.BE.07.0 09 - SILICATES (Germanates)

09.B - Sorosilicates

09.BE -Si2O7 groups with additional anions;

09.BE.07.0 Orthochevkinite* (Ce,La,Ca,Na,Th)4(Fe,Mg)2(Ti,Fe)3Si4O22 Unk Ortho

Other Orthochevkinite Information

References:

NAME( Dana8) PHYS. PROP.(Dana8)

See Also:

Links to other databases for Orthochevkinite :
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

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

Orthochevkinite

(Ce,La,Ca,Na,Th)4(Fe++,Mg)2(Ti,Fe+++)3Si4O22
Dana No: 56.02.08.04 Strunz No: 09.BE.07.0
Locality:

Notes:

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