Sahamalite-(Ce) Mineral Data

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General Sahamalite-(Ce) Information

Chemical Formula:

(Mg,Fe++)Ce2(CO3)4

Composition:

Molecular Weight = 552.46 gm

Cerium 50.72 % Ce 59.41 % Ce₂O₃

Magnesium 3.30 % Mg 5.47 % MgO

Iron 2.53 % Fe 3.25 % FeO

Carbon 8.70 % C 31.86 % CO₂

Oxygen 34.75 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Mg_0.75Fe²⁺_0.25Ce₂(CO₃)₄

Environment:

Accessory mineral in a rare-earth-bearing barite-dolomite carbonatite.

IMA Status:

Valid Species (Pre-IMA) 1953

Locality:

Sulfide Queen mine, Mountain Pass, San Bernardino Co., California, USA. Link to MinDat.org Location Data.

Name Origin:

Named for Thure Georg Sahama (1910-1983), Finnish geochemist and petrologist, University of Helsinki, Helsinki, Finland.

Name Pronunciation:

Sahamalite-(Ce) + Pronunciation

Synonym:

ICSD 31271

PDF 6-189

Sahamalite-(Ce) Image

Images:

Sahamalite-(Ce)

Comments: White granular aggregate of sahamalite-(Ce) on matrix.
Location: Silfide Queen Deposit, Mountain Pass Mine, San Bernandino Co., California, USA. Scale: Specimen Size 9x7x5 mm.
© Sergey Vasiliev / Systematic Mineralogy

Sahamalite-(Ce) Crystallography

Axial Ratios:

a:b:c =1.0357:1:0.2856

Cell Dimensions:

a = 16.79, b = 16.21, c = 4.63, Z = 6; beta = 106.7° V = 1,206.98 Den(Calc)= 4.56

Crystal System:

Monoclinic - PrismaticH-M Symbol (2/m) Space Group: P 2₁/a

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

By Intensity(I/I_o): 2.87(1), 3.65(1), 3.9(1),

Crystal Structure:

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Pertlik F , Preisinger A , Tschermaks Mineralogische und Petrographische Mitteilungen , 31 (1983) p.39-46, Crystal structure of sahamalite (Mg,Fe)RE2(CO3)4, Locality: Mountain Pass mine, San Bernardino County, California

Physical Properties of Sahamalite-(Ce)

Cleavage:

{010} Indistinct

Color:

Colorless.

Density:

4.3

Diaphaneity:

Transparent

Streak:

white

Optical Properties of Sahamalite-(Ce)

Gladstone-Dale:

CI meas= -0.032 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= 0.026 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1654,KPDmeas= 0.1753,KC= 0.1698
Ncalc = 1.73 - 1.77

Optical Data:

Biaxial (-), a=1.679, b=1.776, g=1.807, bire=0.1280, 2V(Calc)=56, 2V(Meas)=57.

Calculated Properties of Sahamalite-(Ce)

Electron Density:

Bulk Density (Electron Density)=4.15 gm/cc
note: Specific Gravity of Sahamalite-(Ce) =4.56 gm/cc.

Fermion Index:

Fermion Index = 0.0049587627
Boson Index = 0.9950412373

Photoelectric:

PE_{Sahamalite-(Ce)}= 258.21 barns/electron
U=PE_{Sahamalite-(Ce)} x r_electron=1,072.05 barns/cc.

Radioactivity:

GRapi = 49,262.21 (Gamma Ray American Petroleum Institute Units)
Concentration of Sahamalite-(Ce) per GRapi unit = 20.30 (PPM)

Sahamalite-(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) 617.44 ±154.36 grams of pure Sahamalite-(Ce) .

**Estimated Radioactivity from Sahamalite-(Ce)** - weak
Specimen Size Weight/Volume (Sphere) *	Calculated Activity Becquerels (Bq)	Calculated Activity Curies (Ci)	Estimated Activity GR(api)	Estimated Exposure (mRem**)/hr If Held in Hand For One Hour
1000 gm / 7.48 cm	1,136,224	3.07E-05	49,262.21	16.20
100 gm / 3.47 cm	113,622	3.07E-06	4,926.22	1.62
10 gm / 1.61 cm	11,362	3.07E-07	492.62	0.16
1 gm / 7.48 mm	1,136	3.07E-08	49.26	0.02
0.1 gm / 3.47 mm	114	3.07E-09	4.93	0.00
0.01 gm / 1.61 mm	11	3.07E-10	0.49	0.00
0.001 gm / 0.75 mm	1	3.07E-11	0.05	0.00

Weight of pure Sahamalite-(Ce) in grams (gm) and Calculated Diameter of a Sphere with a Density of 4.56 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 ( 2.54 % Th) From Sum REE Elements (50.72 % REE)

Sahamalite-(Ce) Classification

Dana Class:

14.04.02.01 (14)Anhydrous Carbonates

(14.04)with Compound Formula A+2 B++2 (CO3)4

(14.04.02)Dana Group

14.04.02.01 Sahamalite-(Ce) (Mg,Fe)Ce2(CO3)4 P 2₁/a 2/m

14.04.02.02 Paratooite-(La)! REE3(Ca,Sr)2NaCu(CO3)8 P 222 or P 222₁ 2 2 2

Strunz Class:

05.AD.05 05 - CARBONATES (NITRATES)

05.A - Carbonates without additional anions, without H2O

05.AD -With rare-earth elements (REE)

05.AD.05 Sahamalite-(Ce) (Mg,Fe)Ce2(CO3)4 P 2₁/a 2/m

Other Sahamalite-(Ce) Information

References:

NAME( MinRec) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Sahamalite-(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
13 - WWW-MINCRYST

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

Sahamalite-(Ce)

(Mg,Fe++)Ce2(CO3)4
Dana No: 14.04.02.01 Strunz No: 05.AD.05
Locality:

Notes: