Davisite Mineral Data

General Davisite Information

Chemical Formula:

Ca(Sc,Ti+++,Mg,Ti++++)AlSiO6

Composition:

Molecular Weight = 235.70 gm

Calcium 16.83 % Ca

Yttrium 0.38 % Y

Magnesium 1.65 % Mg

Zirconium 1.55 % Zr

Scandium 9.54 % Sc

Titanium 5.28 % Ti

Aluminum 11.10 % Al

Vanadium 0.43 % V

Iron 0.24 % Fe

Silicon 12.27 % Si

Oxygen 40.73 % O

______

100.00 %

Empirical Formula:

Ca_0.99Sc_0.5Ti_0.16Mg_0.16Ti_0.1Zr_0.04V³⁺_0.02Fe²⁺_0.01Y_0.01Si_1.03Al_0.97O₆

Environment:

Observed in an ultra-refractory inclusion. Pyroxene group.

IMA Status:

Approved IMA 2008 (Dana # Added)

Locality:

Allende meteorite, Pueblito de Allende, Chihuahua, Mexico Link to MinDat.org Location Data.

Name Origin:

Named for Andrew M. Davis (b 1950), Professor of Cosmochemistry at the University of Chicago, in honor of his outstanding contributions to meteorite research.

Synonym:

IMA2008-030

Davisite Image

Images:

Davisite

Comments: BSE image of the davisite-containing refractory inclusion in a polished section (USNM 7555). (AmMin, v94:845).
Location: Allende meteorite. Scale: See Image.
© American Mineralogist

Davisite Crystallography

Axial Ratios:

a:b:c =1.0996:1:0.6059

Cell Dimensions:

a = 9.884, b = 8.988, c = 5.446, Z = 4; beta = 105.86° V = 465.39 Den(Calc)= 3.36

Crystal System:

Monoclinic - Prismatic H-M Symbol (2/m) Space Group: C 2/c

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

By Intensity(I/I_o): 3.039(1)(221), 2.564(0.47)(221), 2.619(0.4)(002),2.989(0.31)(310), 2.6(0.26)(131), 1.676(0.2)(223), 1.444(0.18)(531), 2.159(0.18)(331), 2.943(0.18)(311),

Physical Properties of Davisite

Diaphaneity:

Transparent

Fracture:

Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.

Habit:

Microscopic Crystals - Crystals visible only with microscopes.

Luster:

Vitreous (Glassy)

Optical Properties of Davisite

Optical Data:

Biaxial (?)

Calculated Properties of Davisite

Electron Density:

Bulk Density (Electron Density)=3.30 gm/cc
note: Specific Gravity of Davisite =3.36 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Davisite= 7.75 barns/electron
U=PE_Davisite x rElectron Density= 25.55 barns/cc.

Radioactivity:

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

Davisite Classification

Dana Class:

65.01.03a.07 (65)Inosilicate Single-Width Unbranched Chains, W=1

(65.01)with chains P=2

(65.01.03a)C2/c clinopyroxenes (Ca clinopyroxenes)

65.01.03a.01 Diopside CaMgSi2O6 C 2/c 2/m

65.01.03a.02 Hedenbergite CaFeSi2O6 C 2/c 2/m

65.01.03a.03 Augite (Ca,Na)(Mg,Fe,Al,Ti)(Si,Al)2O6 C 2/c 2/m

65.01.03a.04 Johannsenite CaMnSi2O6 C 2/c 2/m

65.01.03a.05 Petedunnite Ca(Zn,Mn,Fe,Mg)Si2O6 C 2/c 2/m

65.01.03a.06 Esseneite CaFeAlSiO6 C 2/c 2/m

65.01.03a.07 Davisite! Ca(Sc,Ti,Mg,Ti)AlSiO6 C 2/c 2/m

Strunz Class:

09.DA.15 09 - SILICATES (Germanates)

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

09.DA -Inosilicates with 2-periodic single chains, Si2O6; pyroxene family

09.DA.15 Augite (Ca,Na)(Mg,Fe,Al,Ti)(Si,Al)2O6 C 2/c 2/m

09.DA.15 Esseneite CaFeAlSiO6 C 2/c 2/m

09.DA.15 Diopside CaMgSi2O6 C 2/c 2/m

09.DA.15 Johannsenite CaMnSi2O6 C 2/c 2/m

09.DA.15 Hedenbergite CaFeSi2O6 C 2/c 2/m

09.DA.15 Petedunnite Ca(Zn,Mn,Fe,Mg)Si2O6 C 2/c 2/m

09.DA.15 Davisite! Ca(Sc,Ti,Mg,Ti)AlSiO6 C 2/c 2/m

Other Davisite Information

References:

NAME( AmMin, v94:845) PHYS. PROP.(AmMin, v94:845) OPTIC PROP.(AmMin, v94:845)

See Also:

Links to other databases for Davisite :
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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Print or Cut-and-Paste your Davisite Specimen Label here :

Davisite

Ca(Sc,Ti+++,Mg,Ti++++)AlSiO6
Dana No: 65.01.03a.07 Strunz No: 09.DA.15
Locality:

Notes:

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