Shannonite
A valid IMA mineral species
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About Shannonite
David Shannon
Formula:
Pb2O(CO3)
Colour:
White
Lustre:
Waxy
Hardness:
3 - 3½
Specific Gravity:
7.46 (Calculated)
Crystal System:
Orthorhombic
Name:
Named in honor of David Shannon (18 December 1942, Moline, Illinois, USA - 2 January 2004, Mesa, Arizona, USA), prolific Arizona mineral collector and dealer. He helped collect the first specimens of the mineral.
A lead oxycarbonate that can form naturally under highly oxidising conditions, but also from heating cerussite (e.g., during fire-setting methods used in ore extraction underground; during mine fires).
Chemically related to grootfonteinite and UM1995-03-CO:Pb.
Chemically related to grootfonteinite and UM1995-03-CO:Pb.
Unique Identifiers
Mindat ID:
3632
Long-form identifier:
mindat:1:1:3632:6
Similar Names
IMA Classification of Shannonite
Approved
IMA Formula:
Pb2+2O(CO3)
Approval year:
1993
Type description reference:
Classification of Shannonite
5.BE.05
5 : CARBONATES (NITRATES)
B : Carbonates with additional anions, without H2O
E : With Pb, Bi
5 : CARBONATES (NITRATES)
B : Carbonates with additional anions, without H2O
E : With Pb, Bi
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Snn | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Physical Properties of Shannonite
Waxy
Transparency:
Opaque
Colour:
White
Streak:
White
Hardness:
3 - 3½ on Mohs scale
Tenacity:
Brittle
Fracture:
Irregular/Uneven
Density:
7.46(15) g/cm3 (Calculated)
Optical Data of Shannonite
Type:
Biaxial (+)
RI values:
nα = 1.642 nβ = 1.645 nγ = 1.654
2V:
Measured: 52° , Calculated: 62°
Max. Birefringence:
δ = 0.012
Based on recorded range of RI values above.
Based on recorded range of RI values above.
Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
Surface Relief:
High (positive)
Relative to Canada balsam mounting medium (n ≈ 1.537).
Relative to Canada balsam mounting medium (n ≈ 1.537).
This shows the grain boundary and Becke line effect under plane-polarised
light, based on the contrast between this mineral's average refractive
index and the mounting medium. It does not take into account mineral
colouration.
In focus
Interference Figure:
This shows the idealized biaxial acute bisectrix (Bxa) interference figure
- the conoscopic view for a grain cut perpendicular to the acute bisectrix, using
this mineral's 2V. The two small white dots mark the melatopes - the points
where the two optic axes emerge - and are shown only when they fall within the
field of view. The coloured bands are isochromatics, and the dark bands are
isogyres.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Dispersion:
relatively weak
Colour in reflected light:
white
Chemistry of Shannonite
Mindat Formula:
Pb2O(CO3)
Elements listed:
Crystallography of Shannonite
Crystal System:
Orthorhombic
Class (H-M):
222 - Disphenoidal
Space Group:
P212121
Cell Parameters:
a = 9.014(1) Å, b = 9.315(1) Å, c = 5.1465(7) Å
Ratio:
a:b:c = 0.968 : 1 : 0.552
Unit Cell V:
432.13 ų (Calculated from Unit Cell)
Z:
4
Crystal Structure
Load
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Show
Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
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Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
Remove metal-metal sticks
Display Options
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
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2D | Stereo | Red-Blue | Red-Cyan
View
CIF File Best | x | y | z | a | b | c
CIF File Best | x | y | z | a | b | c
Rotation
Stop | Start
Stop | Start
Labels
Console Off | On | Grey | Yellow
Console Off | On | Grey | Yellow
Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure
| ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
|---|---|---|---|---|---|---|---|
| 0014550 | Shannonite | Krivovichev S V, Burns P C (2000) Crystal chemistry of basic lead carbonates. I. Crystal structure of synthetic shannonite, Pb2O(CO3) Mineralogical Magazine 64 1063-1068 |  | 2000 | synthetic | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 3.215 Å | (100) |
| 3.181 Å | (90) |
| 4.02 Å | (40) |
| 2.858 Å | (40) |
| 2.564 Å | (35) |
| 6.49 Å | (30) |
| 4.14 Å | (30) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 47c : [Carbonates, phosphates, borates, nitrates] | |
| 47h : [Near-surface oxidized, dehydrated minerals] | |
| Stage 10b: Anthropogenic minerals | <10 Ka |
| 55 : Anthropogenic mine minerals |
Type Occurrence of Shannonite
Place of Conservation of Type Material:
Canadian Geological Survey, Ottawa, Canada, 67216; The Natural History Museum, London, England, 1993,487.
Associated Minerals at Type Locality:
Synonyms of Shannonite
Other Language Names for Shannonite
Common Associates
Associations Based on Photo Data:
| 5 photos of Shannonite associated with Cerussite | PbCO3 |
| 3 photos of Shannonite associated with Minium | Pb3O4 |
| 2 photos of Shannonite associated with Massicot | PbO |
| 2 photos of Shannonite associated with Litharge | PbO |
| 1 photo of Shannonite associated with Linarite | PbCu(SO4)(OH)2 |
| 1 photo of Shannonite associated with Caledonite | Pb5Cu2(SO4)3(CO3)(OH)6 |
| 1 photo of Shannonite associated with Hematite | Fe2O3 |
Related Minerals - Strunz-mindat Grouping
| 5.BE.X | Abellaite | NaPb2(CO3)2(OH) |
| 5.BE.10 | Hydrocerussite | Pb3(CO3)2(OH)2 |
| 5.BE.15 | Plumbonacrite | Pb5O(OH)2(CO3)3 |
| 5.BE.20 | Phosgenite | Pb2CO3Cl2 |
| 5.BE.25 | Bismutite | (BiO)2CO3 |
| 5.BE.30 | Kettnerite | CaBiCO3OF |
| 5.BE.35 | Beyerite | Ca(BiO)2(CO3)2 |
| 5.BE.40 | Grootfonteinite | Pb3O(CO3)2 |
| 5.BE.45 | Somersetite | Pb8O2(OH)2(CO3)5 |
Other Information
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Internet Links for Shannonite
mindat.org URL:
https://www.mindat.org/min-3632.html
Please feel free to link to this page.
Please feel free to link to this page.
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External Links:
Mineral Dealers:
References for Shannonite
Reference List:
Roberts, A. C., Stirling, J. A. R., Carpenter, G. J. C., Criddle, A. J., Jones, G. C., Birkett, T. C., Birch, W. D. (1995) Shannonite, Pb2OCO3, a new mineral from the Grand Reef Mine, Graham County, Arizona, USA. Mineralogical Magazine, 59 (395) 305-310 doi:10.1180/minmag.1995.059.395.14
Jambor, John L., Pertsev, Nikolai N., Roberts, Andrew C. (1996) New mineral names. American Mineralogist, 81. 249-254
Localities for Shannonite
Showing 9 localities.
symbol to view information about a locality.
The Locality List
- 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).
All localities listed without proper references should be considered as questionable.
Australia | |
| Birch et al. (1997) |
France | |
| Kolitsch (1997) |
Germany | |
| Schlomann et al. (1990) |
Greece | |
| Rieck et al. (1999) +1 other reference |
| no description given yet] +1 other reference | |
| Rieck et al. (2018) |
USA (TL) | |
| Roberts et al. (1995) |
| Grant et al. (2005) |
| Grant et al. (2005) |
Quick NavTopAbout ShannoniteUnique IdentifiersSimilar NamesIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography Crystal StructureX-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesCommon AssociatesStrunz-MindatOther InformationInternet Links References Localities Locality List
Tonopah-Belmont Mine, Belmont Mountain, Tonopah, Osborn Mining District, Maricopa County, Arizona, USA