Chudobaite Mineral Data

General Chudobaite Information

Chemical Formula:

(Mg,Zn)5(AsO3OH)2(AsO4)2•10(H2O)

Composition:

Molecular Weight = 953.87 gm

Magnesium 6.88 % Mg 11.41 % MgO

Zinc 15.77 % Zn 19.62 % ZnO

Arsenic 31.42 % As 48.19 % As₂O₅

Hydrogen 2.32 % H 20.78 % H₂O

Oxygen 43.61 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Mg_2.7Zn_2.3(AsO₄)₂(AsO₃OH)₂•10(H₂O)

Environment:

Deep oxidation zone of a dolostone-hosted hydrothermal polymetallic ore deposit.

IMA Status:

Approved IMA 1960

Locality:

Tsumeb, Namibia. Link to MinDat.org Location Data.

Name Origin:

Name for Karl Franz Chudoba (1898-1915), Professor of Mineralogy, University of Bonn, Germany.

Synonym:

ICSD 267

PDF 12-643

Chudobaite Crystallography

Axial Ratios:

a:b:c =0.743:1:0.6332

Cell Dimensions:

a = 7.944, b = 10.691, c = 6.77, Z = 1; alpha = 80.97°, beta = 84.2°, gamma = 81.85° V = 559.23 Den(Calc)= 2.83

Crystal System:

Triclinic - Pinacoidal H-M Symbol ( 1) Space Group: P1

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

By Intensity(I/I_o): 10.163(1), 2.979(0.9), 3.44(0.8),

Physical Properties of Chudobaite

Cleavage:

{010} Very Good, {100} Good

Color:

Pink, Rose, White, Colorless.

Density:

2.94

Diaphaneity:

Transparent

Habit:

Euhedral Crystals - Occurs as well-formed crystals showing good external form.

Hardness:

2.5-3 - Finger Nail-Calcite

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Chudobaite

Gladstone-Dale:

CI meas= -0.021 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= -0.061 (Fair) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2148,KPDmeas= 0.2068,KC= 0.2025
Ncalc = 1.57 - 1.6

Optical Data:

Biaxial (-), a=1.583, b=1.608, g=1.633, bire=0.0500, 2V(Calc)=88, 2V(Meas)=79.

Calculated Properties of Chudobaite

Electron Density:

Bulk Density (Electron Density)=2.86 gm/cc
note: Specific Gravity of Chudobaite =2.94 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Chudobaite= 28.92 barns/electron
U=PE_Chudobaite x rElectron Density= 82.62 barns/cc.

Radioactivity:

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

Chudobaite Classification

Dana Class:

39.02.06.01 (39)Hydrated Acid Phosphates, etc

(39.02)H2 (AB)5 (XO4)4 ï¿½ x(H2O)

(39.02.06)Dana Group

39.02.06.01 Chudobaite (Mg,Zn)5(AsO3OH)2(AsO4)2•10(H2O) P1 1

39.02.06.02 Geigerite Mn5(AsO3OH)2(AsO4)2•10(H2O) P1 1

Strunz Class:

08.CE.05 08 - PHOSPHATES, ARSENATES, VANADATES

08.C - Phosphates without Additional Anions, with H2O

08.CE -With only medium-sized cations, RO4:H2O ï¿½ 1:2.5

08.CE.05 Chudobaite (Mg,Zn)5(AsO3OH)2(AsO4)2•10(H2O) P1 1

08.CE.05 Geigerite Mn5(AsO3OH)2(AsO4)2•10(H2O) P1 1

Other Chudobaite Information

References:

NAME( AntBidBlaNic4) PHYS. PROP.(AntBidBlaNic4) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Chudobaite :
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

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Chudobaite

(Mg,Zn)5(AsO3OH)2(AsO4)2•10(H2O)
Dana No: 39.02.06.01 Strunz No: 08.CE.05
Locality:

Notes:

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