Mineralogy Database

Ewaldite Mineral Data

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General Ewaldite Information

Help on Chemical  Formula: Chemical Formula: (Ba,Sr)(Ca,Na,Y,Ce)(CO3)2
Help on Composition: Composition: Molecular Weight = 294.76 gm
   Barium     34.94 %  Ba   39.01 % BaO
   Sodium      2.34 %  Na    3.15 % Na2O
   Strontium   7.43 %  Sr    8.79 % SrO
   Calcium     6.80 %  Ca    9.51 % CaO
   Cerium      4.75 %  Ce    5.57 % Ce2O3
   Yttrium     3.02 %  Y     3.83 % Y2O3
   Carbon      8.15 %  C    29.86 % CO2
   Oxygen     32.57 %  O
             ______        ______ 
             100.00 %       99.73 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Ba0.75Sr0.25Ca0.5Na0.3Y0.1Ce0.1(CO3)2
Help on Environment: Environment: Eocene-aged lacustrine deposits.
Help on IMA Status: IMA Status: Approved IMA 1971
Help on Locality: Locality: Green River Formation, Sweetwater County, Wyoming, USA. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Paul P. Ewald (1888-1985), German crystallographer, founder of Acta Crystallographica, and professor at Brooklyn Polytechnical Institute, New, York.
Help on Name Pronunciation: Name Pronunciation: Ewaldite Say EWALDITE
Help on Synonym: Synonym: ICSD 27421
  PDF 46-1453
 

Ewaldite Crystallography

Help on Axial Ratios: Axial Ratios: a:c = 1:2.41387
Help on Cell Dimensions: Cell Dimensions: a = 5.318, c = 12.837, Z = 2; V = 314.41 Den(Calc)= 3.11
Help on Crystal System: Crystal System: Hexagonal - Dihexagonal Pyramidal H-M Symbol (6mm) Space Group: P 63mc
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 6.39(1), 3.72(0.4), 4.58(0.2),1.714(0.1), 2.44(0.1), 3.2(0.1),
 

Physical Properties of Ewaldite

Help on Cleavage: Cleavage: None
Help on Color: Color: Bluish green, Greenish gray, White.
Help on Density: Density: 3.25
Help on Diaphaneity: Diaphaneity: Transparent
Help on Habit: Habit: Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).
Help on Streak: Streak: white
 

Optical Properties of Ewaldite

Help on Dichroism (e): Dichroism (e): pale yellow green.
Help on Dichroism (w): Dichroism (w): dark blue green.
Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.128 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= -0.178 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1958,KPDmeas= 0.1874,KC= 0.1662
Ncalc = 1.52 - 1.54
Help on Optical Data: Optical Data: Uniaxial (-), e=1.572, w=1.646, bire=0.0740.
 

Calculated Properties of Ewaldite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.97 gm/cc
note: Specific Gravity of Ewaldite =3.25 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.06
Boson Index = 0.94
Help on Photoelectric: Photoelectric: PEEwaldite = 191.06 barns/electron
U=PEEwaldite x relectron= 566.67 barns/cc.
Help on Radioactivity: Radioactivity:

GRapi = 4,627.40 (Gamma Ray American Petroleum Institute Units)
Concentration of Ewaldite per GRapi unit = 216.10 (PPM)

Ewaldite is Radioactive as defined in 49 CFR 173.403. Greater than 70 Bq / gram.

Estimated Radioactivity from Ewaldite - mild
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 / 8.38 cm 106,480 2.88E-06 4,627.40 1.52
100 gm / 3.89 cm 10,648 2.88E-07 462.74 0.15
10 gm / 1.80 cm 1,065 2.88E-08 46.27 0.02
1 gm / 8.38 mm 106 2.88E-09 4.63 0.00
0.1 gm / 3.89 mm 11 2.88E-10 0.46 0.00
0.01 gm / 1.80 mm 1 2.88E-11 0.05 0.00
0.001 gm / 0.84 mm 0 2.88E-12 0.00 0.00

Weight of pure Ewaldite in grams (gm) and Calculated Diameter of a Sphere with a Density of 3.25 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 ( 0.24 % Th) From Sum REE Elements ( 4.75 % REE)
 

Ewaldite Classification

Help on  Dana Class: Dana Class: 14.02.04.01 (14)Anhydrous Carbonates
  (14.02)with Compound Formula A+ B++ (CO3)2
  (14.02.04)Dana Group
 
14.02.04.01 Ewaldite (Ba,Sr)(Ca,Na,Y,Ce)(CO3)2 P 63mc 6mm
Help on  Strunz Class: Strunz Class: 05.CC.45 05 - CARBONATES (NITRATES)
  05.C - Carbonates without Additional Anions, with H2O
  05.CC -With rare-earth elements (REE)
 
05.CC.45 Ewaldite (Ba,Sr)(Ca,Na,Y,Ce)(CO3)2 P 63mc 6mm
 

Other Ewaldite Information

Help on References: References: NAME( Dana8) PHYS. PROP.(Dana8) OPTIC PROP.(Dana8)
Help on See Also: See Also: Links to other databases for Ewaldite :
1 - Alkali-Nuts(English)
2 - Alkali-Nuts(Francais)
3 - Am. Min. Crystal Structure Database
4 - Athena
5 - EUROmin Project
6 - Ecole des Mines de Paris
7 - GeoScienceWorld
8 - Google Images
9 - Google Scholar
10 - Handbook of Mineralogy (MinSocAm)
11 - Handbook of Mineralogy (UofA)
12 - MinDAT
13 - Mineralienatlas (Deutsch)
14 - Online Mineral Museum
15 - QUT Mineral Atlas
16 - Ruff.Info

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

Ewaldite

(Ba,Sr)(Ca,Na,Y,Ce)(CO3)2
Dana No: 14.02.04.01 Strunz No: 05.CC.45
Locality:

 

Notes:

 

 
   
 


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