Mineralogy Database

Brassite Mineral Data

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General Brassite Information

Help on Chemical  Formula: Chemical Formula: Mg(AsO3OH)•4(H2O)
Help on Composition: Composition: Molecular Weight = 236.29 gm
   Magnesium  10.29 %  Mg   17.06 % MgO
   Arsenic    31.71 %  As   48.63 % As2O5
   Hydrogen    3.84 %  H    34.31 % H2O
   Oxygen     54.17 %  O
             ______        ______ 
             100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Mg(AsO3OH)•4(H2O)
Help on Environment: Environment: A rare reaction product of arsenic-rich solutions with Ca-Mg carbonates.
Help on IMA Status: IMA Status: Approved IMA 1973
Help on Locality: Locality: From Jachymov (Joachimsthal), Czech Republic. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Honoring Rejane Brasse, who first synthesized the compound.
Help on Name Pronunciation: Name Pronunciation: Brassite Say BRASSITE
Help on Synonym: Synonym: ICSD 78
  PDF 23-1228

Brassite Image

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Comments: Opaque white botryoidal masses of brassite on matrix.
Location: Mine de Salsigne, Aude, France. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Brassite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.686:1:1.5228
Help on Cell Dimensions: Cell Dimensions: a = 7.472, b = 10.891, c = 16.585, Z = 8; V = 1,349.65 Den(Calc)= 2.33
Help on Crystal System: Crystal System: Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: P bca
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 4.97(1), 3.2(0.8), 4.14(0.6),

Physical Properties of Brassite

Help on Cleavage: Cleavage: {001} Perfect
Help on Color: Color: White.
Help on Density: Density: 2.28
Help on Streak: Streak: white

Optical Properties of Brassite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.044 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= -0.021 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2345,KPDmeas= 0.2396,KC= 0.2296
Ncalc = 1.52 - 1.53
Help on Optical Data: Optical Data: Biaxial (+), a=1.531, b=1.546, g=1.562, bire=0.0310

Calculated Properties of Brassite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.33 gm/cc
note: Specific Gravity of Brassite =2.33 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.01
Boson Index = 0.99
Help on Photoelectric: Photoelectric: PEBrassite = 20.91 barns/electron
U=PEBrassite x rElectron Density= 48.66 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Brassite is Not Radioactive

Brassite Classification

Help on  Dana Class: Dana Class: (39)Hydrated Acid Phosphates, etc
  (39.01)A+ [HXO4] � x(H2O)
  (39.01.07)Dana Group Brassite Mg(AsO3OH)•4(H2O) P bca 2/m 2/m 2/m
Help on  Strunz Class: Strunz Class: 08.CE.15 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.15 Brassite Mg(AsO3OH)•4(H2O) P bca 2/m 2/m 2/m

Other Brassite Information

Help on References: References: NAME( AntBidBlaNic4) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)
Help on See Also: See Also: Links to other databases for Brassite :
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.15





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