Bobkingite Mineral Data
General Bobkingite Information
Chemical Formula:
Cu5Cl2(OH)8(H2O)2
Composition:
Molecular Weight = 560.72 gm
Copper 56.66 % Cu 70.93 % CuO
Hydrogen 2.16 % H 19.28 % H2 O
Chlorine 12.65 % Cl 12.65 % Cl
- %
Cl -2.85 % -O=Cl2
Oxygen 28.53 % O
______ ______
100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:
Cu5 Cl2 (OH)8 •2(H2 O)
Environment:
Occurs on crusts of malachite and azurite that overlie massive cuprite in oxidized waste material consisting of quarried diorite with copper inclusions. Similar to atacamite; struct ure
IMA Status:
Approved IMA 2002 (Dana # Added)
Locality:
New Cliffe Hill Quarry, Stanton-under-Bardon, Leicestershire, England. Link to MinDat.org Location Data.
Name Origin:
Named for Robert King, formerly of the Department of Geology, Leicester University, prominent mineral collector and founding member of the Russell Society.
Synonym:
IMA2000-029
Bobkingite Crystallography
Axial Ratios:
a:b:c =1.5242:1:1.3073
Cell Dimensions:
a = 10.301, b = 6.758, c = 8.835, Z = 2; beta = 111.53° V = 572.13 Den(Calc)= 3.25
Crystal System:
Monoclinic - Prismatic H-M Symbol (2/m) Space Group: C 2/m
X Ray Diffraction:
By Intensity(I/Io ): 5.502(1)(110), 8.199(1)(001), 2.883(0.8)(310), 2.188(0.5)(232 ), 1.767(0.4), 2.263(0.4), 2.693(0.4), 5.03(0.4),
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Physical Properties of Bobkingite
Cleavage:
{001} Perfect, {100} Fair
Color:
Pale blue.
Diaphaneity:
Transparent
Fracture:
Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.
Habit:
Microscopic Crystals - Crystals visible only with microscopes.
Habit:
Platy - Sheet forms (e.g. micas).
Hardness:
3 - Calcite
Luster:
Vitreous (Glassy)
Streak:
pale blue
Optical Properties of Bobkingite
Gladstone-Dale:
CI calc = -0.007 (Superior) - where the CI = (1-KPDcalc /KC ) KPDcalc = 0.2276,KC = 0.2261 Ncalc = 1.73
Optical Data:
Biaxial (-), a=1.724, b=1.745, g=1.75, bire=0.0260
Calculated Properties of Bobkingite
Electron Density:
Bulk Density (Electron Density)=3.14 gm/cc note: Specific Gravity of Bobkingite =3.25 gm/cc.
Fermion Index:
Fermion Index = 0.0001401961 Boson Index = 0.9998598039
Photoelectric:
PEBobkingite = 25.58 barns/electronU=PEBobkingite x r Electron Density= 80.35 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Bobkingite is Not Radioactive
Bobkingite Classification
Dana Class:
10.05.08.02 (10) Oxyhalides and Hydroxyhalides
(10.05) where Am (O,OH)p Xq
(10.05.08) Dana Group
10.05.08.01 Simonkolleite Zn5(OH)8Cl2•(H2O) R 3 m 3 2/m
10.05.08.02 Bobkingite ! Cu5Cl2(OH)8(H2O)2 C 2/m 2/m
Strunz Class:
03.DA.50 03 - HALIDES
03.D - Oxyhalides, Hydroxyhalides and Related Double Halides
03.DA -With Cu, etc., without Pb
03.DA.50 Bobkingite ! Cu5Cl2(OH)8(H2O)2 C 2/m 2/m
Other Bobkingite Information
References:
NAME( AmMin, Vol 88, p 251) PHYS. PROP.(AmMin, Vol 88, p 251) OPTIC PROP.(AmMin, Vol 88, p 251)
See Also:
Links to other databases for Bobkingite :
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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Bobkingite
Cu5Cl2(OH)8(H2O)2
Dana No: 10.05.08.02 Strunz No: 03.DA.50
Locality:
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