Burgessite Mineral Data
General Burgessite Information
Chemical Formula:
Co2(H2O)4[(AsO3OH)]2•(H2O)
Composition:
Molecular Weight = 487.36 gm
Calcium 0.16 % Ca 0.23 % CaO
Cobalt 21.16 % Co 26.91 % CoO
Nickel 2.77 % Ni 3.52 % NiO
Arsenic 30.75 % As 47.16 % As2 O5
Hydrogen 2.48 % H 22.18 % H2 O
Oxygen 42.68 % O
______ ______
100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:
Co1.75 Ni0.23 Ca0.02 (AsO3 OH)2 •5(H2 O)
Environment:
Purchased as mineral specimen labeled "erythrite" from a mineral dealer; the sample consists of pink rosettes on matrix and was collected in the 1920s. .New structure type.
IMA Status:
Approved IMA 2007 (Dana # Added)
Locality:
Keeley mine, South Lorrain Township, Timiskaming District, Ontario, Canada. Link to MinDat.org Location Data.
Name Origin:
Named for David S. Burgess (born April 18, 1951) of Newington, Connecticut, U.S.A.
Synonym:
IMA2007-055
Burgessite Image
Images:
Burgessite
Comments: Rosettes of burgessite showing the individual lath-like crystals and their adamantine luster. (CanMin, v47:159).
Location: Keeley mine, South Lorrain Township, Timiskaming District, Ontario, Canada..
Scale: Picture size 1.1 mm.
© Canadian Mineralogist
Images:
Burgessite
Comments: SEM photographs of a rosette of burgessite. (CanMin, v47:159).
Location: Keeley mine, South Lorrain Township, Timiskaming District, Ontario, Canada..
Scale: Picture size50 µm.
© Canadian Mineralogist
Burgessite Crystallography
Axial Ratios:
a:b:c =0.506:1:1.3698
Cell Dimensions:
a = 4.7058, b = 9.299, c = 12.738, Z = 2; beta = 98.933° V = 550.64 Den(Calc)= 2.94
Crystal System:
Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 21 /n
X Ray Diffraction:
By Intensity(I/Io ): 7.446(1), 6.267(0.44), 2.998(0.31), 3.725(0.29), 3.26(0.25), 2.596(0.23), 2.97(0.21), 3.089(0.2),
Physical Properties of Burgessite
Cleavage:
{010} Good, {001} Fair
Color:
Purplish pink.
Density:
2.93
Diaphaneity:
Transparent
Fracture:
Brittle - Irregular - Very brittle fracture producing irregular fragments
Habit:
Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).
Habit:
Rosette - Bundled tabular aggregates resembling rose flower petals.
Hardness:
3 - Calcite
Luster:
Adamantine
Streak:
pale pink
Optical Properties of Burgessite
Gladstone-Dale:
CI meas = -0.006 (Superior) - where the CI = (1-KPDmeas /KC ) CI calc = -0.003 (Superior) - where the CI = (1-KPDcalc /KC )
KPDcalc = 0.2073,KPDmeas = 0.208,KC = 0.2067 Ncalc = 1.61
Optical Data:
Biaxial (+), a=1.596, b=1.604, g=1.628, bire=0.0320
Calculated Properties of Burgessite
Electron Density:
Bulk Density (Electron Density)=2.85 gm/cc note: Specific Gravity of Burgessite =2.94 gm/cc.
Fermion Index:
Fermion Index = 0.0005237727 Boson Index = 0.9994762273
Photoelectric:
PEBurgessite = 28.90 barns/electronU=PEBurgessite x r Electron Density= 82.33 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Burgessite is Not Radioactive
Burgessite Classification
Dana Class:
39.01.11.01 (39) Hydrated Acid Phosphates, etc
(39.01) A+ [HXO4] � x(H2O)
(39.01.11) Dana Group
39.01.11.01 Burgessite ! Co2(H2O)4[(AsO3OH)]2•(H2O) P 21 /n 2/m
Strunz Class:
08.CB.60 08 - PHOSPHATES, ARSENATES, VANADATES
08.C - Phosphates without Additional Anions, with H2O
08.CB -With only medium-sized cations, RO4:H2O = 1:1
08.CB.60 Burgessite ! Co2(H2O)4[(AsO3OH)]2•(H2O) P 21 /n 2/m
Other Burgessite Information
References:
NAME( CanMin, v47:159) PHYS. PROP.(CanMin, v47:159) OPTIC PROP.(CanMin, v47:159)
See Also:
Links to other databases for Burgessite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - GeoScienceWorld
4 - Google Images
5 - Google Scholar
6 - MinDAT
7 - Mineralienatlas (Deutsch)
8 - Online Mineral Museum
9 - QUT Mineral Atlas
10 - Ruff.Info
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Print or Cut-and-Paste your Burgessite Specimen Label here :
Burgessite
Co2(H2O)4[(AsO3OH)]2•(H2O)
Dana No: 39.01.11.01 Strunz No: 08.CB.60
Locality:
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