Mineralogy Database

Keiviite-(Yb) Mineral Data

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General Keiviite-(Yb) Information

Help on Chemical  Formula: Chemical Formula: (Yb,Y)2Si2O7
Help on Composition: Composition: Molecular Weight = 472.18 gm
   Yttrium     9.41 %  Y    11.96 % Y2O3
   Ytterbium  54.97 %  Yb   62.59 % Yb2O3
   Silicon    11.90 %  Si   25.45 % SiO2
   Oxygen     23.72 %  O
             ______        ______ 
             100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Yb1.5Y0.5Si2O7
Help on Environment: Environment: Found in an "amazonite" pegmatite with fluorite.
Help on IMA Status: IMA Status: Approved IMA 1983
Help on Locality: Locality: Keivy, Kola Peninsula, Russia Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for the locality and the ytterbium content.
Help on Name Pronunciation: Name Pronunciation: Keiviite-(Yb) Say KEIVIITE-(YB)

Keiviite-(Yb) Image

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Comments: White massive blebs of keiviite-(Yb) in blue-green fluorite.
Location: Mount Ploskaja, west Keivy, Kola, Russia. Scale: See Image.
© Rruff Database

Keiviite-(Yb) Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.7671:1:0.5321
Help on Cell Dimensions: Cell Dimensions: a = 6.84, b = 8.916, c = 4.745, Z = 2; beta = 102.11° V = 282.94 Den(Calc)= 5.54
Help on Crystal System: Crystal System: Monoclinic - Prismatic H-M Symbol (2/m) Space Group: C 2/m
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 3.2(1), 3.24(1), 3.03(0.09),

Physical Properties of Keiviite-(Yb)

Help on Cleavage: Cleavage: {???} Perfect
Help on Color: Color: Colorless.
Help on Density: Density: 5.95
Help on Diaphaneity: Diaphaneity: Transparent
Help on Hardness: Hardness: 4-5 - Fluorite-Apatite
Help on Luminescence: Luminescence: Cathodoluminescence, Short UV=faint green.
Help on Luster: Luster: Vitreous (Glassy)
Help on Streak: Streak: white

Optical Properties of Keiviite-(Yb)

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.077 (Fair) - where the CI = (1-KPDmeas/KC)
CI calc= 0.009 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1353,KPDmeas= 0.126,KC= 0.1365
Ncalc = 1.76 - 1.81
Help on Optical Data: Optical Data: Biaxial (-), a=1.723, b=1.758, g=1.768, bire=0.0450

Calculated Properties of Keiviite-(Yb)

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=4.89 gm/cc
note: Specific Gravity of Keiviite-(Yb) =5.54 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.17
Boson Index = 0.83
Help on Photoelectric: Photoelectric: PEKeiviite-(Yb) = 565.62 barns/electron
U=PEKeiviite-(Yb) x relectron=2,767.34 barns/cc.
Help on Radioactivity: Radioactivity:

GRapi = 51,783.07 (Gamma Ray American Petroleum Institute Units)
Concentration of Keiviite-(Yb) per GRapi unit = 19.31 (PPM)

Keiviite-(Yb) 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) 587.39 ±146.85 grams of pure Keiviite-(Yb) .

Estimated Radioactivity from Keiviite-(Yb) - weak
Curies (Ci)
If Held in Hand
For One Hour
1000 gm / 7.01 cm 1,231,341 3.33E-05 51,783.07 17.02
100 gm / 3.25 cm 123,134 3.33E-06 5,178.31 1.70
10 gm / 1.51 cm 12,313 3.33E-07 517.83 0.17
1 gm / 7.01 mm 1,231 3.33E-08 51.78 0.02
0.1 gm / 3.25 mm 123 3.33E-09 5.18 0.00
0.01 gm / 1.51 mm 12 3.33E-10 0.52 0.00
0.001 gm / 0.70 mm 1 3.33E-11 0.05 0.00

Weight of pure Keiviite-(Yb) in grams (gm) and Calculated Diameter of a Sphere with a Density of 5.54 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 ( 2.75 % Th) From Sum REE Elements (54.97 % REE)

Keiviite-(Yb) Classification

Help on  Dana Class: Dana Class: 55.02.01a.03 (55)Sorosilicate Si2O7 Groups, Generally with No Additional Anions
  (55.02)with cations in [6] coordination
  (55.02.01a)Thortveitite group
55.02.01a.01 Gittinsite CaZrSi2O7 C 2/m 2/m
55.02.01a.02 Keiviite-(Y) (Y,Yb)2Si2O7 C 2/m 2/m
55.02.01a.03 Keiviite-(Yb) (Yb,Y)2Si2O7 C 2/m 2/m
55.02.01a.04 Thortveitite (Sc,Y)2Si2O7 C 2/m 2/m
Help on  Strunz Class: Strunz Class: 09.BC.05 09 - SILICATES (Germanates)
  09.B - Sorosilicates
  09.BC -Si2O7 groups, without non-tetrahedral anions;
09.BC.05 Keiviite-(Y) (Y,Yb)2Si2O7 C 2/m 2/m
09.BC.05 Gittinsite CaZrSi2O7 C 2/m 2/m
09.BC.05 Keiviite-(Yb) (Yb,Y)2Si2O7 C 2/m 2/m
09.BC.05 Thortveitite (Sc,Y)2Si2O7 C 2/m 2/m
09.BC.05 Yttrialite-(Y) (Y,Th)2Si2O7 P 21/m 2/m

Other Keiviite-(Yb) Information

Help on References: References: NAME( Dana8) 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 Keiviite-(Yb) :
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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Dana No: 55.02.01a.03 Strunz No: 09.BC.05





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