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Geigerite Mineral Data

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General Geigerite Information

Help on Chemical  Formula: Chemical Formula: Mn5(AsO3OH)2(AsO4)2•10(H2O)
Help on Composition: Composition: Molecular Weight = 1,012.54 gm
   Manganese  27.13 %  Mn   35.03 % MnO
   Arsenic    29.60 %  As   45.40 % As2O5
   Hydrogen    2.19 %  H    19.57 % H2O
   Oxygen     41.08 %  O
             ______        ______ 
             100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Mn2+5(AsO3OH)2(AsO4)2•10(H2O)
Help on Environment: Environment: Cavities in radiolarites, formed by metamorphism of manganese oxide ores.
Help on IMA Status: IMA Status: Approved IMA 1989
Help on Locality: Locality: Falotta mine, Oberhalbstein, Graub�unden, Switzerland. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Thomas Geiger (1886-1976), Wiesendangen, Switzerland, who studied Falotta manganese ores.
Help on Name Pronunciation: Name Pronunciation: Geigerite + Pronunciation Say GEIGERITE
Help on Synonym: Synonym: ICSD 68637
  PDF 45-1347

Geigerite Image

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Comments: Small, brownish grains of transparent geigerite (see lower image) in a silicous breccia.
Location: Mt. Nero Mine, Borghetto di Vara, La Spieza, Italy. Scale: 3.5 x 1.5 cm.
© Rich Geiger

Geigerite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.743:1:0.6332
Help on Cell Dimensions: 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)= 3.01
Help on Crystal System: Crystal System: Triclinic - Pinacoidal H-M Symbol ( 1) Space Group: P1
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 10.45(1), 3.051(0.24), 3.507(0.21),

Physical Properties of Geigerite

Help on Cleavage: Cleavage: {???} Perfect
Help on Color: Color: Red, Colorless.
Help on Density: Density: 3.05
Help on Diaphaneity: Diaphaneity: Transparent to Translucent
Help on Hardness: Hardness: 3 - Calcite
Help on Luster: Luster: Vitreous - Pearly
Help on Streak: Streak: white

Optical Properties of Geigerite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.012 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.005 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2101,KPDmeas= 0.2067,KC= 0.2091
Ncalc = 1.63 - 1.64
Help on Optical Data: Optical Data: Biaxial (-), a=1.601, b=1.63, g=1.66, bire=0.0590, 2V(Calc)=88, 2V(Meas)=89.

Calculated Properties of Geigerite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.89 gm/cc
note: Specific Gravity of Geigerite =3.00 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0002004855
Boson Index = 0.9997995145
Help on Photoelectric: Photoelectric: PEGeigerite = 26.95 barns/electron
U=PEGeigerite x rElectron Density= 77.78 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Geigerite is Not Radioactive

Geigerite Classification

Help on  Dana Class: Dana Class: (39)Hydrated Acid Phosphates, etc
  (39.02)H2 (AB)5 (XO4)4 � x(H2O)
  (39.02.06)Dana Group Chudobaite (Mg,Zn)5(AsO3OH)2(AsO4)2•10(H2O) P1 1 Geigerite Mn5(AsO3OH)2(AsO4)2•10(H2O) P1 1
Help on  Strunz Class: 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 Geigerite Information

Help on References: References: NAME( AntBidBlaNic4) PHYS. PROP.(Am.Min.,Vol.74,p676-684,1989) OPTIC PROP.(Am.Min.,Vol.74,p676-684,1989)
Help on See Also: See Also: Links to other databases for Geigerite :
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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Dana No: Strunz No: 08.CE.05





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