Achavalite Mineral Data

General Achavalite Information

Chemical Formula:

FeSe

Composition:

Molecular Weight = 134.81 gm

Iron 41.43 % Fe

Selenium 58.57 % Se

______

100.00 %

Empirical Formula:

Fe²⁺Se

Environment:

Same as synthetic delta-Fe7S8 with niccolite structure type. Needs additional work.

IMA Status:

Valid Species (Pre-IMA) 1939 (Dana # Added)

Locality:

Cerro de Cacheuta, Mendoza, Argentina. Link to MinDat.org Location Data.

Name Origin:

Named for L. Achaval.

Synonym:

ICSD 29308

PDF 26-795

Achavalite Crystallography

Axial Ratios:

a:c = 1:1.63531

Cell Dimensions:

a = 3.636, c = 5.946, Z = 2; V = 68.08 Den(Calc)= 6.58

Crystal System:

Hexagonal - Dihexagonal Dipyramidal H-M Symbol (6/m 2/m 2/m) Space Group: P 6₃/mmc

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

By Intensity(I/I_o): 2.778(1), 2.159(0.9), 1.815(0.7),

Physical Properties of Achavalite

Color:

Gray.

Density:

6.53

Diaphaneity:

Opaque

Hardness:

2.5 - Finger Nail

Luster:

Metallic

Calculated Properties of Achavalite

Electron Density:

Bulk Density (Electron Density)=5.86 gm/cc
note: Specific Gravity of Achavalite =6.58 gm/cc.

Fermion Index:

Fermion Index = 0.05
Boson Index = 0.95

Photoelectric:

PE_Achavalite= 59.64 barns/electron
U=PE_Achavalite x rElectron Density= 349.34 barns/cc.

Radioactivity:

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

Achavalite Classification

Dana Class:

02.08.11.11 (02)Sulfides - Including Selenides and Tellurides

(02.08)where Am Bn Xp, with (m+n):p=1:1

(02.08.11)Nickeline Group (Hexagonal: P63/mmc)

02.08.11.01 Nickeline NiAs P 6₃/mmc 6/m 2/m 2/m

02.08.11.02 Breithauptite NiSb P 6₃/mmc 6/m 2/m 2/m

02.08.11.03 Sederholmite NiSe P 6₃/mmc 6/m 2/m 2/m

02.08.11.04 Hexatestibiopanickelite (Ni,Pd)(Te,Sb) P 6₃/mmc 6/m 2/m 2/m

02.08.11.05 Sudburyite (Pd,Ni)Sb P 6₃/mmc 6/m 2/m 2/m

02.08.11.06 Kotulskite Pd(Te,Bi) P 6₃/mmc 6/m 2/m 2/m

02.08.11.07 Sobolevskite PdBi P 6₃/mmc 6/m 2/m 2/m

02.08.11.08 Stumpflite Pt(Sb,Bi) P 6₃/mmc 6/m 2/m 2/m

02.08.11.09 Langisite (Co,Ni)As P 6₃/mmc 6/m 2/m 2/m

02.08.11.10 Freboldite CoSe P 6₃/mmc 6/m 2/m 2/m

02.08.11.11 Achavalite! FeSe P 6₃/mmc 6/m 2/m 2/m

02.08.11.12 Sorosite! Cu(Sn,Sb) P 6₃/mmc 6/m 2/m 2/m

02.08.11.13 Vavrinite! Ni2SbTe2 P 6₃/mmc 6/m 2/m 2/m

Strunz Class:

02.CC.05 02 - SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulf

02.C - Metal Sulfides, M:S = 1:1 (and similar)

02.CC -With Ni, Fe, Co, PGE, etc.

02.CC.05 Achavalite FeSe P 6₃/mmc 6/m 2/m 2/m

02.CC.05 Breithauptite NiSb P 6₃/mmc 6/m 2/m 2/m

02.CC.05 Freboldite CoSe P 6₃/mmc 6/m 2/m 2/m

02.CC.05 Hexatestibiopanickelite (Ni,Pd)(Te,Sb) P 6₃/mmc 6/m 2/m 2/m

02.CC.05 Langisite (Co,Ni)As P 6₃/mmc 6/m 2/m 2/m

02.CC.05 Jaipurite* CoS P 6₃/mmc 6/m 2/m 2/m

02.CC.05 Kotulskite Pd(Te,Bi) P 6₃/mmc 6/m 2/m 2/m

02.CC.05 Nickeline NiAs P 6₃/mmc 6/m 2/m 2/m

02.CC.05 Zlatogorite! CuNiSb2 P 3m1 3 2/m

02.CC.05 Sederholmite NiSe P 6₃/mmc 6/m 2/m 2/m

02.CC.05 Stumpflite Pt(Sb,Bi) P 6₃/mmc 6/m 2/m 2/m

02.CC.05 Sudburyite (Pd,Ni)Sb P 6₃/mmc 6/m 2/m 2/m

02.CC.05 Sobolevskite PdBi P 6₃/mmc 6/m 2/m 2/m

Other Achavalite Information

References:

PHYS. PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Achavalite :
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 - MinDAT
9 - Mineralienatlas (Deutsch)
10 - Online Mineral Museum
11 - QUT Mineral Atlas
12 - Ruff.Info
13 - WWW-MINCRYST

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Achavalite

FeSe
Dana No: 02.08.11.11 Strunz No: 02.CC.05
Locality:

Notes:

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