Cobaltomenite Mineral Data

General Cobaltomenite Information

Chemical Formula:

CoSeO3•2(H2O)

Composition:

Molecular Weight = 221.92 gm

Cobalt 26.56 % Co 37.37 % Co₂O₃

Hydrogen 1.82 % H 16.24 % H₂O

Selenium 35.58 % Se 50.00 % SeO₂

Oxygen 36.05 % O

______ ______

100.00 % 103.60 % = TOTAL OXIDE

Empirical Formula:

CoSeO₃•2(H₂O)

Environment:

Secondary mineral in the oxidation zone of hydrothermal selenium-sulfide bearing vein deposits.

IMA Status:

Valid Species (Pre-IMA) 1882

Locality:

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

Name Origin:

Named for the content of cobalt and the Greek for moon.

Cobaltomenite Image

Images:

Cobaltomenite

Comments: Purple micro crystals of cobaltomenite on matrix.
Location: Paris #25 mine, Thompson district, Utah, USA. Scale: 2.5 x 2 cm.
© John Veevaert

Cobaltomenite Crystallography

Axial Ratios:

a:b:c =0.8657:1:0.7383

Cell Dimensions:

a = 7.64, b = 8.825, c = 6.516, Z = 4; beta = 98.6° V = 434.39 Den(Calc)= 3.39

Crystal System:

Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 2₁/n

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

By Intensity(I/I_o): 3.015(1), 5.72(0.95), 3.8(0.72),

Physical Properties of Cobaltomenite

Cleavage:

None

Color:

Dark red, Pink.

Density:

3.39

Diaphaneity:

Transparent

Fracture:

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

Hardness:

2-2.5 - Gypsum-Finger Nail

Luster:

Vitreous (Glassy)

Streak:

dark pink

Optical Properties of Cobaltomenite

Gladstone-Dale:

CI meas= 0.223 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= 0.223 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2142,KPDmeas= 0.2142,KC= 0.2756
Ncalc = 1.93

Optical Data:

Biaxial (-), a=1.681, b=1.728, g=1.769, bire=0.0880, 2V(Calc)=82, 2V(Meas)=83.

Calculated Properties of Cobaltomenite

Electron Density:

Bulk Density (Electron Density)=3.21 gm/cc
note: Specific Gravity of Cobaltomenite =3.39 gm/cc.

Fermion Index:

Fermion Index = 0.02
Boson Index = 0.98

Photoelectric:

PE_{Cobaltomenite}= 35.71 barns/electron
U=PE_{Cobaltomenite} x rElectron Density= 114.55 barns/cc.

Radioactivity:

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

Cobaltomenite Classification

Dana Class:

34.02.03.02 (34)Selenites - Tellurites - Sulfites

(34.02)as A++ XO3 ï¿½ x(H2O)

(34.02.03)Chalcomenite Group (Monoclinic)

34.02.03.01 Clinochalcomenite CuSeO3•2(H2O) P 2₁/n 2/m

34.02.03.02 Cobaltomenite CoSeO3•2(H2O) P 2₁/n 2/m

34.02.03.03 Ahlfeldite (Ni,Co)SeO3•2(H2O) P 2₁/m 2/m

Strunz Class:

04.JH.10 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate

04.J - Arsenites, Antimonites, Bismuthites, Sulfites,

04.JH -Selenites without additional anions, with H2O

04.JH.10 Ahlfeldite (Ni,Co)SeO3•2(H2O) P 2₁/m 2/m

04.JH.10 Clinochalcomenite CuSeO3•2(H2O) P 2₁/n 2/m

04.JH.10 Cobaltomenite CoSeO3•2(H2O) P 2₁/n 2/m

Other Cobaltomenite Information

References:

NAME( AntBidBlaNic5) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Cobaltomenite :
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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Cobaltomenite

CoSeO3•2(H2O)
Dana No: 34.02.03.02 Strunz No: 04.JH.10
Locality:

Notes:

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