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 % As2 O5
Hydrogen 2.32 % H 20.78 % H2 O
Oxygen 43.61 % O
______ ______
100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:
Mg2.7 Zn2.3 (AsO4 )2 (AsO3 OH)2 •10(H2 O)
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
X Ray Diffraction:
By Intensity(I/Io ): 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:
PEChudobaite = 28.92 barns/electronU=PEChudobaite x r Electron 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 � 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 � 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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