Metakottigite Mineral Data
General Metakottigite Information
Chemical Formula:
(Zn,Fe+++,Fe++)3(AsO4)2•8((H2O),OH)
Composition:
Molecular Weight = 603.71 gm
Zinc 18.41 % Zn 22.92 % ZnO
Iron 12.03 % Fe 15.47 % FeO
Arsenic 24.82 % As 38.07 % As2 O5
Hydrogen 2.34 % H 20.89 % H2 O
Oxygen 42.40 % O
______ ______
100.00 % 97.35 % = TOTAL OXIDE
Empirical Formula:
Zn1.7 Fe2+ 1.3 (AsO4 )2 •6(H2 O)(OH)2
Environment:
Secondary mineral from the oxide zone of an arsenic-rich polymetallic mineral deposit, formed by oxidation and concomitant dehydrogenization of ferroan kottigite.
IMA Status:
Approved IMA 1982
Locality:
Ojuela mine, Mapimi, Durango, Mexico. Link to MinDat.org Location Data.
Name Origin:
Named for its dimorphous relationship to kottigite, and by analogy to metavivianite.
Name Pronunciation:
Metakottigite + Pronunciation
Synonym:
Metakoettigite
Metakottigite Image
Images:
Metakottigite Crystallography
Axial Ratios:
a:b:c =0.8432:1:0.5
Cell Dimensions:
a = 7.96, b = 9.44, c = 4.72, Z = 1; alpha = 95.6°, beta = 97°, gamma = 107.8° V = 333.58 Den(Calc)= 3.01
Crystal System:
Triclinic - Pinacoidal H-M Symbol ( 1 ) Space Group: P1
X Ray Diffraction:
By Intensity(I/Io ): 6.909(1), 8.898(0.4), 3.926(0.3),
Physical Properties of Metakottigite
Cleavage:
{110} Perfect
Color:
Gray.
Diaphaneity:
Transparent to Translucent
Habit:
Tabular - Form dimensions are thin in one direction.
Habit:
Twinning Common - Crystals are usually twinned.
Hardness:
1.5-2.5 - Hardness very near Gypsum
Optical Properties of Metakottigite
Gladstone-Dale:
CI calc = -0.139 (Poor) - where the CI = (1-KPDcalc /KC ) KPDcalc = 0.2256,KC = 0.198 Ncalc = 1.6
Optical Data:
Biaxial (+), a=1.648, b=1.68, g=1.716, bire=0.0680, 2V(Calc)=90, 2V(Meas)=93.
Pleochroism (x):
deep blue.
Pleochroism (y):
yellow.
Pleochroism (z):
light yellow.
Calculated Properties of Metakottigite
Electron Density:
Bulk Density (Electron Density)=2.93 gm/cc note: Specific Gravity of Metakottigite =3.02 gm/cc.
Fermion Index:
Fermion Index = 0.01 Boson Index = 0.99
Photoelectric:
PEMetakottigite = 29.33 barns/electronU=PEMetakottigite x r Electron Density= 85.92 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Metakottigite is Not Radioactive
Metakottigite Classification
Dana Class:
40.03.08.02 (40) Hydrated Phosphates, etc
(40.03) where (A++)3 (XO4)2 � x(H2O)
(40.03.08) Dana Group
40.03.08.01 Symplesite Fe3(AsO4)2•8(H2O) P1 1
40.03.08.02 Metakottigite (Zn,Fe,Fe)3(AsO4)2•8((H2O),OH) P1 1
Strunz Class:
08.CE.85 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.85 Metavivianite (Fe3-x,Fex)(PO4)2(OH)x•8-x(H2O),x=0.5 P1 or P1 Tri
08.CE.85 Metakottigite (Zn,Fe,Fe)3(AsO4)2•8((H2O),OH) P1 1
Other Metakottigite Information
References:
NAME( AntBidBlaNic4) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(AntBidBlaNic4)
See Also:
Links to other databases for Metakottigite :
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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Metakottigite
(Zn,Fe+++,Fe++)3(AsO4)2•8((H2O),OH)
Dana No: 40.03.08.02 Strunz No: 08.CE.85
Locality:
Notes:
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