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 % As₂O₅

Hydrogen 2.48 % H 22.18 % H₂O

Oxygen 42.68 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Co_1.75Ni_0.23Ca_0.02(AsO₃OH)₂•5(H₂O)

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

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 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:

PE_Burgessite= 28.90 barns/electron
U=PE_Burgessite x rElectron 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] ï¿½ 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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