Chivruaiite Mineral Data

General Chivruaiite Information

Chemical Formula:

Ca4(Ti,Nb)5[(Si6O17)2[(OH,O)5]•13-14H2O

Composition:

Molecular Weight = 1,585.23 gm

Potassium 1.09 % K 1.31 % K₂O

Sodium 0.07 % Na 0.10 % Na₂O

Strontium 0.22 % Sr 0.26 % SrO

Calcium 7.58 % Ca 10.61 % CaO

Titanium 12.47 % Ti 20.81 % TiO₂

Manganese 0.03 % Mn 0.04 % MnO

Niobium 2.58 % Nb 3.69 % Nb₂O₅

Aluminum 0.03 % Al 0.06 % Al₂O₃

Iron 0.14 % Fe 0.20 % Fe₂O₃

Silicon 21.26 % Si 45.48 % SiO₂

Hydrogen 1.95 % H 17.43 % H₂O

Oxygen 52.56 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Ca₃K_0.44Na_0.05Sr_0.04Mn²⁺_0.01Ti_4.13Nb_0.44Fe³⁺_0.04Al_0.02Si₁₂O₃₄(OH)_4.51O_0.49ï¿½13.08(H₂O)

Environment:

Found in three different hydrothermal veins within the Khibiny and Lovozero alkaline massifs associated with microcline, eudialyte, natrolite, astrophyllite, aegirine, etc. Ca-analo g of zorite.

IMA Status:

Approved IMA 2004 (Dana # Added)

Locality:

Chivruai river valley, Lovozero massif, Kola Peninsula, Russia Link to MinDat.org Location Data.

Name Origin:

Named for the locality.

Synonym:

IMA2004-052

Chivruaiite Image

Images:

Chivruaiite

Comments: SEM image of radiating aggregate of chivruaiite from a microcline vein in eudialyte-bearing lujavrite. (AmMin, v91, p923).
Location: Chivruai River valley, the Lovozero massif, Khibiny massif, Kola peninsula, Russia. Scale: See Image.
© American Mineralogist

Chivruaiite Crystallography

Axial Ratios:

a:b:c =0.312:1:0.302

Cell Dimensions:

a = 7.17, b = 22.98, c = 6.94, Z = 1; V = 1,143.48 Den(Calc)= 2.30

Crystal System:

Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: C mmm

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

By Intensity(I/I_o): 11.6(1)(020 ), 6.91(0.9)(110,001 ), 3.04(0.8)(221,240 ),2.58(0.5), 3.35(0.5)(061,151 ), 3.41(0.5)(220 ), 5.23(0.5)(130 ), 2.97(0.4),

Physical Properties of Chivruaiite

Cleavage:

{100} Distinct, {010} Distinct

Color:

Pale pink, Colorless.

Density:

2.4 - 2.42, Average = 2.41

Diaphaneity:

Transparent

Fracture:

Brittle - Splintery - Brittle fracture leaving splintery fragments.

Habit:

Acicular - Occurs as needle-like crystals.

Habit:

Aggregates - Made of numerous individual crystals or clusters.

Habit:

Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite)

Hardness:

3 - Calcite

Luster:

Vitreous (Glassy)

Streak:

wjhite

Optical Properties of Chivruaiite

Gladstone-Dale:

CI meas= 0.011 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.037 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2817,KPDmeas= 0.2689,KC= 0.2718
Ncalc = 1.63 - 1.66

Optical Data:

Biaxial (+), a=1.612, b=1.627, g=1.705, bire=0.0930, 2V(Calc)=50, 2V(Meas)=40. Dispersion r > v.

Calculated Properties of Chivruaiite

Electron Density:

Bulk Density (Electron Density)=2.42 gm/cc
note: Specific Gravity of Chivruaiite =2.41 gm/cc.

Fermion Index:

Fermion Index = 0.02
Boson Index = 0.98

Photoelectric:

PE_Chivruaiite= 7.80 barns/electron
U=PE_Chivruaiite x r_electron= 18.89 barns/cc.

Radioactivity:

GRapi = 15.74 (Gamma Ray American Petroleum Institute Units)
Concentration of Chivruaiite per GRapi unit = 6.35 (%)

Estimated Radioactivity from Chivruaiite - barely detectable

Chivruaiite Classification

Dana Class:

66.03.01.07 (66)Inosilicate Double-Width Unbranched Chains, W=2

(66.03)with chains P>2

(66.03.01)P=3

66.03.01.01 Xonotlite Ca6Si6O17(OH)2 P 2/a 2/m

66.03.01.02 Zorite Na6Ti5[Si12O34](O,OH)5•11(H2O) C mmm 2/m 2/m 2/m

66.03.01.03 Eudidymite NaBeSi3O7(OH) C 2/c 2/m

66.03.01.04 Epididymite NaBeSi3O7(OH) Pnam 2/m 2/m 2/m

66.03.01.05 Yuksporite (Sr,Ba)2K4(Ca,Na)14([],Mn,Fe){(Ti,Nb)4(O,OH)4[Si6O17]2[Si2O7]3}(H2O,OH)n,n~3 P 2₁/m 2/m

66.03.01.06 Haineaultite! (Na,Ca)5Ca(Ti,Nb)5(Si,S)12O34(OH,F)8•5(H2O) C 222 2 2 2

66.03.01.07 Chivruaiite! Ca4(Ti,Nb)5[(Si6O17)2[(OH,O)5]•13-14H2O C mmm 2/m 2/m 2/m

Strunz Class:

09.DG.45 09 - SILICATES (Germanates)

09.D - Inosilicates* Structural terminology according to Liebau (1985)

09.DG -Inosilicates with 3-periodic single and multiple chains

09.DG.45 Zorite Na6Ti5[Si12O34](O,OH)5•11(H2O) C mmm 2/m 2/m 2/m

09.DG.45 Chivruaiite! Ca4(Ti,Nb)5[(Si6O17)2[(OH,O)5]•13-14H2O C mmm 2/m 2/m 2/m

Other Chivruaiite Information

References:

NAME( AmMin, v91, p922) PHYS. PROP.(AmMin, v91, p922) OPTIC PROP.(AmMin, v91, p922)

See Also:

Links to other databases for Chivruaiite :
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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Chivruaiite

Ca4(Ti,Nb)5[(Si6O17)2[(OH,O)5]•13-14H2O
Dana No: 66.03.01.07 Strunz No: 09.DG.45
Locality:

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