Schaferite Mineral Data

General Schaferite Information

Chemical Formula:

NaCa2Mg2(VO4)3

Composition:

Molecular Weight = 496.57 gm

Sodium 4.63 % Na 6.24 % Na₂O

Calcium 16.14 % Ca 22.59 % CaO

Magnesium 9.79 % Mg 16.23 % MgO

Vanadium 30.78 % V 54.94 % V₂O₅

Oxygen 38.66 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

NaCa₂Mg₂(VO₄)₃

Environment:

Found in a silicate-rich xenolith in leucite tephrite lava. The magnesium dominant analogue of palenzonaite. A member of the Garnet group.

IMA Status:

Approved IMA 1998 (Dana # Added)

Locality:

Bellberg volcano, near Mayen, Laacher See district, Eifel, Germany. Link to MinDat.org Location Data.

Name Origin:

Named after Helmut Schï¿½fer (b. 1931), amateur mineralogist from Mayen-Kï¿½rrenberg, specialist in the minerals of the Eifel volcanic area, who discovered the mineral.

Name Pronunciation:

Schaferite + Pronunciation

Synonym:

IMA1997-048

Schaferite Crystallography

Cell Dimensions:

a = 12.427, Z = 8; V = 1,919.11 Den(Calc)= 3.44

Crystal System:

Isometric - Hexoctahedral H-M Symbol (4/m 3 2/m) Space Group: I a3d

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

By Intensity(I/I_o): 2.779(1), 3.108(0.44), 1.662(0.4),

Physical Properties of Schaferite

Cleavage:

None

Color:

Red, Orange red.

Diaphaneity:

Transparent

Fracture:

Conchoidal - Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).

Habit:

Octahedral Crystals - Occurs as octahedral shaped crystals.

Hardness:

5 - Apatite

Luster:

Vitreous (Glassy)

Streak:

yellow

Optical Properties of Schaferite

Gladstone-Dale:

CI calc= 0.019 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2733,KC= 0.2786
Ncalc = 1.96

Optical Data:

Isotropic, n=1.94.

Calculated Properties of Schaferite

Electron Density:

Bulk Density (Electron Density)=3.33 gm/cc
note: Specific Gravity of Schaferite =3.44 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Schaferite= 8.18 barns/electron
U=PE_Schaferite x rElectron Density= 27.21 barns/cc.

Radioactivity:

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

Schaferite Classification

Dana Class:

38.02.01.04 (38)Anhydrous Phosphates, etc

(38.02)(A+ B++)5 (XO4)3

(38.02.01)Berzeliite Group

38.02.01.01 Berzeliite (Ca,Na)3(Mg,Mn)2(AsO4)3 I a3d 4/m 3 2/m

38.02.01.02 Manganberzeliite (Ca,Na)3(Mn,Mg)2(AsO4)3 I a3d 4/m 3 2/m

38.02.01.03 Palenzonaite (Ca,Na)3Mn(V,As,Si)3O12 I a3d 4/m 3 2/m

38.02.01.04 Schaferite! NaCa2Mg2(VO4)3 I a3d 4/m 3 2/m

Strunz Class:

08.AC.25 08 - PHOSPHATES, ARSENATES, VANADATES

08.A - Phosphates, etc. without additional anions, without H2O

08.AC -With medium-sized and large cations

08.AC.25 Berzeliite (Ca,Na)3(Mg,Mn)2(AsO4)3 I a3d 4/m 3 2/m

08.AC.25 Palenzonaite (Ca,Na)3Mn(V,As,Si)3O12 I a3d 4/m 3 2/m

08.AC.25 Manganberzeliite (Ca,Na)3(Mn,Mg)2(AsO4)3 I a3d 4/m 3 2/m

08.AC.25 Schaferite! NaCa2Mg2(VO4)3 I a3d 4/m 3 2/m

Other Schaferite Information

References:

NAME( CanMin, 8/99) PHYS. PROP.(AmMin, V 84, p 1687) OPTIC PROP.(MinRec)

See Also:

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

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

Schaferite

NaCa2Mg2(VO4)3
Dana No: 38.02.01.04 Strunz No: 08.AC.25
Locality:

Notes:

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