Keiviite-(Y) Mineral Data

[Newest Minerals] [Rare Minerals] [Cabinet Specimens] [About Us] [Image Gallery]
Dakota Matrix Minerals
Updated weekly, for the collector, educator, and researcher since 1996
Extensive Inventory of very Rare Minerals. Visa and Mastercard are Welcome

General Keiviite-(Y) Information

Chemical Formula:

(Y,Yb)2Si2O7

Composition:

Molecular Weight = 388.05 gm

Yttrium 34.37 % Y 43.64 % Y₂O₃

Ytterbium 22.30 % Yb 25.39 % Yb₂O₃

Silicon 14.48 % Si 30.97 % SiO₂

Oxygen 28.86 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Y_1.5Yb_0.5Si₂O₇

Environment:

In fissures in quartz and fluorite in \amazonite" pegmatites.

IMA Status:

Approved IMA 1985

Locality:

Mt. Ploskaya, Keivy massif, Kola Peninsula, Russia. Link to MinDat.org Location Data.

Name Origin:

Named for the relation to keiviite-(Yb) and the yttrium content.

Name Pronunciation:

Keiviite-(Y)

Search for Keiviite-(Y) Images

Images:

Image not yet available on Webmineral.com

Try searching images.google.com or Mindat Picture Gallary for mineral pictures. Caution: The images retrieved may not be appropriate.

Keiviite-(Y) Crystallography

Axial Ratios:

a:b:c =0.7639:1:0.5283

Cell Dimensions:

a = 6.845, b = 8.96, c = 4.734, Z = 2; beta = 101.65° V = 284.36 Den(Calc)= 4.53

Crystal System:

Monoclinic - PrismaticH-M Symbol (2/m) Space Group: C 2/m

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

By Intensity(I/I_o): 3.23(1), 4.65(0.9), 3.04(0.8),

Physical Properties of Keiviite-(Y)

Cleavage:

{110} Perfect, {001} Indistinct

Color:

Colorless, White, Pink brown.

Density:

4.45

Diaphaneity:

Transparent

Hardness:

4-5 - Fluorite-Apatite

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Keiviite-(Y)

Gladstone-Dale:

CI meas= -0.012 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.006 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1633,KPDmeas= 0.1662,KC= 0.1642
Ncalc = 1.73 - 1.74

Optical Data:

Biaxial (-), a=1.713, b=1.748, g=1.758, bire=0.0450, 2V(Calc)=54, 2V(Meas)=55-56.

Calculated Properties of Keiviite-(Y)

Electron Density:

Bulk Density (Electron Density)=4.14 gm/cc
note: Specific Gravity of Keiviite-(Y) =4.53 gm/cc.

Fermion Index:

Fermion Index = 0.07
Boson Index = 0.93

Photoelectric:

PE_Keiviite-(Y)= 261.05 barns/electron
U=PE_Keiviite-(Y) x r_electron=1,081.85 barns/cc.

Radioactivity:

GRapi = 21,757.45 (Gamma Ray American Petroleum Institute Units)
Concentration of Keiviite-(Y) per GRapi unit = 45.96 (PPM)

Keiviite-(Y) is Radioactive as defined in 49 CFR 173.403. Greater than 70 Bq / gram.

**Estimated Radioactivity from Keiviite-(Y)** - weak
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 / 7.50 cm	499,438	1.35E-05	21,757.45	7.15
100 gm / 3.48 cm	49,944	1.35E-06	2,175.74	0.72
10 gm / 1.62 cm	4,994	1.35E-07	217.57	0.07
1 gm / 7.50 mm	499	1.35E-08	21.76	0.01
0.1 gm / 3.48 mm	50	1.35E-09	2.18	0.00
0.01 gm / 1.62 mm	5	1.35E-10	0.22	0.00
0.001 gm / 0.75 mm	0	1.35E-11	0.02	0.00

Weight of pure Keiviite-(Y) in grams (gm) and Calculated Diameter of a Sphere with a Density of 4.53 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 ( 1.11 % Th) From Sum REE Elements (22.30 % REE)

Keiviite-(Y) Classification

Dana Class:

55.02.01a.02 (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

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-(Y) Information

References:

NAME( AntBidBlaNic2) PHYS. PROP.(Am.Min.,Vol.73,p191,1988) OPTIC PROP.(Am.Min.,Vol.73,p191,1988)

See Also:

Links to other databases for Keiviite-(Y) :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - Google Images
4 - Google Scholar
5 - Handbook of Mineralogy (UofA)
6 - MinDAT
7 - MinMax(Deutsch)
8 - MinMax(English)
9 - Mineralienatlas (Deutsch)
10 - QUT Mineral Atlas
11 - Ruff.Info

Search for Keiviite-(Y) using:

[ALTAVISTA] [AOL] [All-The-Web] [HotBot] [Ixquick] [MAMMA] [MSN.COM] [Netscape] [Scirus] [Teoma] [Wikipedia] [YAHOO]

Visit our Advertisers for Keiviite-(Y) :

AA Mineral Specimens

B & L Fine Minerals

Crystalarium.com

Dan Weinrich Fine Minerals

Dan Weinrich Auctions

Dakota Matrix

Desert Winds Gems and Minerals

John Betts Fine Minerals

Mason's Minerals

Mineral News

Mineral of the Month Club

Wrights Rock Shop

Translate Keiviite-(Y) Mineral Data :

Ask about Keiviite-(Y) here :
Ask-A-Mineralogist from the Mineralogical Society of America
Mindat.org's Discussion Groups
Original Rockhounds Discussion Group
Rockhounds Discussion Group on Yahoo Groups
Mineral Discussion Forum from Fabre Minerals - also available in Español

Print or Cut-and-Paste your Keiviite-(Y) Specimen Label here :

Keiviite-(Y)

(Y,Yb)2Si2O7
Dana No: 55.02.01a.02 Strunz No: 09.BC.05
Locality:

Notes: