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Howardevansite Mineral Data
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General Howardevansite Information
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 Chemical Formula: |
NaCu++Fe+++2(VO4)3 |
| Composition: |
Molecular Weight = 543.05 gm |
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Sodium 4.23 % Na 5.71 % Na2O |
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Vanadium 28.14 % V 50.24 % V2O5 |
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Iron 20.57 % Fe 29.41 % Fe2O3 |
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Copper 11.70 % Cu 14.65 % CuO |
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Oxygen 35.35 % O |
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______ ______ |
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100.00 % 100.00 % = TOTAL OXIDE |
| Empirical Formula: |
NaCuFe3+2(VO4)3 |
| Environment: |
Forms by sublimation around furaroles on an andesitic volcano. |
| IMA Status: |
Approved IMA 1988 |
| Locality: |
Izalco volcano, El Salvador. Link to MinDat.org Location Data. |
| Name Origin: |
Named for Howard Tasker Evans, Jr. (1919-2000), American mineralogist and crystallographer, U.S.G.S., Reston, Virginia, USA. |
| Name Pronunciation: |
Howardevansite + Pronunciation  |
| Synonym: |
ICSD 202529 |
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PDF 42-1333 |
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Howardevansite Crystallography
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| Axial Ratios: |
a:b:c =0.8388:1:0.6805 |
| Cell Dimensions: |
a = 8.198, b = 9.773, c = 6.651, Z = 2; alpha = 103.82°, beta = 101.99°, gamma = 106.74° V = 484.71 Den(Calc)= 3.72 |
| Crystal System: |
Triclinic - Pinacoidal H-M Symbol ( 1) Space Group: P1 |
| X Ray Diffraction: |
By Intensity(I/Io): 3.093(1), 3.167(1), 1.659(0.7), |
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Physical Properties of Howardevansite
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| Cleavage: |
None |
| Color: |
Black. |
| Diaphaneity: |
Opaque to translucent |
| Fracture: |
Brittle - Generally displayed by glasses and most non-metallic minerals. |
| Habit: |
Tabular - Form dimensions are thin in one direction. |
| Luster: |
Metallic |
| Streak: |
red brown |
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Optical Properties of Howardevansite
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| Optical Data: |
Biaxial (?) |
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NCalc= 2.14 - from Gladstone-Dale relationship (KC = 0.2992) where Ncalc=Dcalc*KC+1
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| RL Anisotrophism: |
Moderate. |
| RL Color: |
Medium gray. |
| Reflectivity |
Standardized Intensity (100%) Reflection Spectra of Howardevansite in Air
| λ |
R1 |
R2 |
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∑ R1(λ) |
∑ R2(λ) |
| 481 nm |
15.50 |
20.10 |
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| 547 nm |
15.00 |
18.40 |
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| 591 nm |
14.10 |
17.20 |
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| 644 nm |
13.50 |
17.10 |
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Calculated Relative Intensity Colors of Howardevansite in Air
Relative
Intensity |
0% |
70% |
100% |
140% |
210% |
280% |
350% |
420% |
490% |
560% |
630% |
| R1 |
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| R2 |
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Calculated Properties of Howardevansite
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| Electron Density: |
Bulk Density (Electron Density)=3.61 gm/cc
note: Specific Gravity of Howardevansite =3.81 gm/cc.
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| Fermion Index: |
Fermion Index = 0.0052336727
Boson Index = 0.9947663273 |
| Photoelectric: |
PEHowardevansite = 17.05 barns/electron
U=PEHowardevansite x rElectron Density= 61.50 barns/cc.
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| Radioactivity: |
GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Howardevansite is Not Radioactive |
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Howardevansite Classification
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| Dana Class: |
38.05.03.01 (38)Anhydrous Phosphates, etc |
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(38.05)with miscellaneous formulae |
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(38.05.03)Dana Group |
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38.05.03.01 Howardevansite NaCuFe2(VO4)3 P1 1 |
| Strunz Class: |
08.AC.05 08 - PHOSPHATES, ARSENATES, VANADATES |
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08.A - Phosphates, etc. without additional anions, without H2O |
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08.AC -With medium-sized and large cations |
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08.AC.05 Howardevansite NaCuFe2(VO4)3 P1 1 |
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Other Howardevansite Information
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| References: |
NAME( AntBidBlaNic4) PHYS. PROP.(Am.Min.,Vol.73,p181-186,1988) OPTIC PROP.(AntBidBlaNic4) |
| See Also: |
Links to other databases for Howardevansite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - GeoScienceWorld
6 - Google Images
7 - Google Scholar
8 - Handbook of Mineralogy (MinSocAm)
9 - Handbook of Mineralogy (UofA)
10 - MinDAT
11 - Mineralienatlas (Deutsch)
12 - Online Mineral Museum
13 - QUT Mineral Atlas
14 - Ruff.Info
15 - WWW-MINCRYST
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Print or Cut-and-Paste your Howardevansite Specimen Label here :
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Howardevansite
NaCu++Fe+++2(VO4)3
Dana No: 38.05.03.01 Strunz No: 08.AC.05
Locality:
Notes:
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