Murdochite (original) (raw)
Specific Gravity:
5.9 - 6.7
Name:
After Professor Joseph Murdoch [February 19, 1890 Washington, D.C., USA – December 31, 1973 Santa Monica, California, USA], professor of mineralogy, University of California, Los Angeles, California, USA. Murdoch was an authority on ore microscopy and ore genesis. He studied, among other things, the California borate minerals, the Crestmore quarries, and pegmatites in northern Brazil. He also served as president of the Mineralogical Society of America.
A secondary mineral found in the oxidized zones of lead-copper deposits.
The Cl analogue of eddavidite with which it forms a solid solution.
Long-form identifier:
mindat:1:1:2812:3
4b640466-1d80-464d-87e7-930ab0629db3
Approved, 'Grandfathered' (first described prior to 1959)
Type description reference:
3.DB.45
3 : HALIDES
D : Oxyhalides, hydroxyhalides and related double halides
B : With Pb, Cu, etc.
4.6.5.1
4 : SIMPLE OXIDES
6 : Miscellaneous
7.11.25
7 : Oxides and Hydroxides
11 : Oxides of Sn and Pb
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
| Symbol | Source | Reference |
|---|---|---|
| Mdh | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Hardness:
VHN100=519 - 567 kg/mm2 - Vickers
Cleavage:
Distinct/Good
On {111}.
Density:
5.9 - 6.7 g/cm3 (Measured) 6.06 g/cm3 (Calculated)
Reflectivity:
| Wavelength | R |
|---|---|
| 470nm | 16.3% |
| 490nm | 16.4% |
| 510nm | 16.7% |
| 530nm | 16.9% |
| 570nm | 17.2% |
| 610nm | 17.5% |
| 630nm | 17.5% |
| 650nm | 17.6% |
Graph shows reflectance levels at different wavelengths (in nm). Top of box is 100%. Peak reflectance is 17.6%.
Colour in reflected light:
Grey with a yellowish brown tint
Comments:
Slightly higher reflectivity values are given in Criddle and Stanley (1993).
Mindat Formula:
Cu12Pb2O15Cl2
Class (H-M):
m_3_m _(_4/_m_32/m ) - Hexoctahedral
Cell Parameters:
a = 9.21 Å
Unit Cell V:
781.23 ų (Calculated from Unit Cell)
Morphology:
Crystals octahedral and cubo-octahedral.
Twinning:
Common on unstated law.
Comment:
Cell parameter data: a = 9.210-9.224 Å.
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| ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
|---|---|---|---|---|---|---|---|
| 0000075 | Murdochite | Christ C L, Clark J R (1955) The crystal structure of murdochite disordered model American Mineralogist 40 907-916 |  |
1955 | 0 | 293 | |
| 0000076 | Murdochite | Christ C L, Clark J R (1955) The crystal structure of murdochite ordered model American Mineralogist 40 907-916 | |
1955 | 0 | 293 | |
| 0009907 | Murdochite | Winkler B, Chall M, Pickard C J, Milman V, White J (2000) Structure of Cu6PbO8 This model appears to be the stable phase at ambient conditions Acta Crystallographica B56 22-26 |  |
2000 | 0 | 293 | |
| 0009981 | Murdochite | Dubler E, Vedani A, Oswald H R (1983) New structure determination of murdochite, Cu6PbO8 Acta Crystallographica C39 1143-1146 | |
1983 | Hansonburg mining district, New Mexico, USA | 0 | 293 |
CIF Raw Data - click here to close
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Radiation - Copper Kα
Data Set:
Data courtesy of RRUFF project at University of Arizona, used with permission.
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 5.30 Å | (100) |
| 2.659 Å | (100) |
| 1.629 Å | (100) |
| 2.303 Å | (90) |
| 2.109 Å | (90) |
| 3.25 Å | (80) |
| 2.776 Å | (80) |
Comments:
Tiger, Arizona, USA. Data from Christ and Clark (1955).
General Appearance of Type Material:
Tiny black opaque octahedra up to one millimeter in the longest dimension on the surface of, and embedded within, plates of wulfenite and on the surface of crystals of fluorite.
Place of Conservation of Type Material:
No designated type material.
Geological Setting of Type Material:
An oxidized Pb–Cu deposit.
Associated Minerals at Type Locality:
Reference:
Fahey, J.J. (1955) Murdochite, a new copper lead oxide mineral. American Mineralogist: 40: 905-906.
Associated Minerals Based on Photo Data:
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Reference List:
Dunn, Pete J., Fleischer, Michael, Francis, Carl A., Langley, Richard H., Kissin, Stephen A., Shigley, Hames E., Vanko, David A., Zilczer, Janet A. (1984) New mineral names. American Mineralogist, 69 (7-8) 810-815
Winkler, Björn, Chall, Michael, Pickard, Chris J., Milman, Victor, White, Jim (2000) Structure of Cu6PbO8. Acta Crystallographica Section B Structural Science, 56 (1) 22-26 doi:10.1107/s0108768199011015
This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the 
symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.
- This locality has map coordinates listed. - This locality has estimated coordinates. ⓘ - Click for references and further information on this occurrence. ? - Indicates mineral may be doubtful at this locality. 
- Good crystals or important locality for species. 
- World class for species or very significant. (TL) - Type Locality for a valid mineral species. (FRL) - First Recorded Locality for everything else (eg varieties). Struck out - Mineral was erroneously reported from this locality. Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).
All localities listed without proper references should be considered as questionable.