Schiavinatoite Mineral Data

General Schiavinatoite Information

Chemical Formula:

(Nb,Ta)BO4

Composition:

Molecular Weight = 209.97 gm

Tantalum 41.36 % Ta 50.51 % Ta₂O₅

Niobium 23.01 % Nb 32.91 % Nb₂O₅

Boron 5.15 % B 16.58 % B₂O₃

Oxygen 30.48 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Nb_0.52Ta_0.48(BO₄)

Environment:

In miarolitic cavities and intergranular mineral in a B-rich granitic pegmatite. Nb-analogue of behierite.

IMA Status:

Approved IMA 2001 (Dana # Added)

Locality:

Antsongombato, south of Betafo, Malagasy Republic. Link to MinDat.org Location Data.

Name Origin:

Named for Italian mineralogist Giuseppe Schiavinato (1915-1996).

Synonym:

IMA1999-051

Schiavinatoite Image

Images:

Schiavinatoite

Comments: Black, 3mm euhedral crystal of schiavinatoite in matrix.
Location: Ampanodiana Sud, Tetezantsio, Mahaiza, Madagascar. Scale: 3x2x2cm.
© Tom Loomis / Dakota Matrix

Images:

Schiavinatoite Rynersonite

Comments: Brown, columnar schiavinatoite with minor white rynersonite sticks on quartz.
Location: Ampanodiana Sud, Tetezantsio, Mahaiza, Antananarivo, Madagascar. Scale: See Image.
© Jeff Weissman / Photographic Guide to Mineral Species

Schiavinatoite Crystallography

Axial Ratios:

a:c = 1:0.88229

Cell Dimensions:

a = 6.219, c = 5.487, Z = 4; V = 212.22 Den(Calc)= 6.57

Crystal System:

Tetragonal - Ditetragonal DipyramidalH-M Symbol (4/m 2/m 2/m) Space Group: I 4₁/amd

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

By Intensity(I/I_o): 4.115(1)(101), 3.11(0.84)(200), 2.328(0.49)(112),1.598(0.42)(312), 2.481(0.36)(211), 1.939(0.29)(301),

Crystal Structure:

Mouse
drag1 - LMB Manipulate Structure
drag2 - RMB Resize/Rotate
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S - Stereo Pair on/off
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Demartin F , Diella V , Gramaccioli C M , Pezzotta F , European Journal of Mineralogy , 13 (2001) p.159-165, Schiavinatoite, (Nb,Ta)BO4, the Nb analogue of behierite

Physical Properties of Schiavinatoite

Cleavage:

None

Color:

Grayish pink.

Diaphaneity:

Transparent

Fracture:

Brittle - Generally displayed by glasses and most non-metallic minerals.

Habit:

Granular - Generally occurs as anhedral to subhedral crystals in matrix.

Hardness:

8 - Topaz

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Schiavinatoite

Gladstone-Dale:

CI calc= 0.011 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1979,KC= 0.2001
Ncalc = 2.31

Optical Data:

Uniaxial (+), e=2.3.

Calculated Properties of Schiavinatoite

Electron Density:

Bulk Density (Electron Density)=5.84 gm/cc
note: Specific Gravity of Schiavinatoite =6.57 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_{Schiavinatoite}= 515.65 barns/electron
U=PE_{Schiavinatoite} x rElectron Density=3,012.62 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Schiavinatoite is Not Radioactive

Schiavinatoite Classification

Dana Class:

24.01.02.02 (24)Borates - Anhydrous

(24.01)where (A)2 XO4

(24.01.02)Dana Group

24.01.02.01 Behierite (Ta,Nb)BO4 I 4₁/amd 4/m 2/m 2/m

24.01.02.02 Schiavinatoite! (Nb,Ta)BO4 I 4₁/amd 4/m 2/m 2/m

Strunz Class:

06.AC.15 06 - BORATES

06.A - Monoborates

06.AC -B(O,OH)4, without and with additional anions; 1(T), 1(T)+OH, etc.

06.AC.15 Behierite (Ta,Nb)BO4 I 4₁/amd 4/m 2/m 2/m

06.AC.15 Schiavinatoite! (Nb,Ta)BO4 I 4₁/amd 4/m 2/m 2/m

Other Schiavinatoite Information

References:

NAME( AmMin, Vol 86, p 1536) PHYS. PROP.(AmMin, Vol 86, p 1536) OPTIC PROP.(AmMin, Vol 86, p 1536)

See Also:

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

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

Schiavinatoite

(Nb,Ta)BO4
Dana No: 24.01.02.02 Strunz No: 06.AC.15
Locality:

Notes: