Sharpite
A valid IMA mineral species - grandfathered
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About Sharpite
Robert R. Sharp
Formula:
Ca(UO2)3(CO3)4 · 3H2O
According to the single-crystal X-ray study (Plášil 2018), an idealized formula of sharpite is Ca(H2O)3[(UO2)3(CO3)3.6O0.2],where the content of (CO3) lies most probably within 4 > xCO3 > 3.5 apfu range.
Colour:
Greenish-yellow, olive-green
Hardness:
2½ - 3
Specific Gravity:
4.412 (Calculated)
Crystal System:
Orthorhombic
Name:
Named after Major Robert Rich Sharp (25 September 1881 Gateshead, Durham County, England - 25 August 1960 Bulawayo, Zimbabwe), discoverer of the uranium deposit at Shinkolobwe, Zaire in 1915.
Sharpite represents a unique sheet-based structure derived from the rutherfordine topology, where one of the hexagons within that topology accomodates Ca2+.
Unique Identifiers
Mindat ID:
3633
Long-form identifier:
mindat:1:1:3633:3
GUID
(UUID V4):
(UUID V4):
c9add895-d343-4f4d-92f2-f8737660173c
IMA Classification of Sharpite
Approved, 'Grandfathered' (first described prior to 1959)
First published:
1938
Classification of Sharpite
5.EA.35
5 : CARBONATES (NITRATES)
E : Uranyl Carbonates
A : UO2:CO3 > 1:1
5 : CARBONATES (NITRATES)
E : Uranyl Carbonates
A : UO2:CO3 > 1:1
16b.7.10.1
16b : HYDRATED CARBONATES CONTAINING HYDROXYL OR HALOGEN
7 : Miscellaneous
16b : HYDRATED CARBONATES CONTAINING HYDROXYL OR HALOGEN
7 : Miscellaneous
11.11.10
11 : Carbonates
11 : Carbonates of Cr and U
11 : Carbonates
11 : Carbonates of Cr and U
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 |
|---|---|---|
| Shp | 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 Sharpite
Transparency:
Translucent
Colour:
Greenish-yellow, olive-green
Hardness:
2½ - 3 on Mohs scale
Density:
4.412 g/cm3 (Calculated)
Comment:
measured > 4.55
Optical Data of Sharpite
Type:
Biaxial (+)
RI values:
nα = 1.632 - 1.638 nγ = 1.720 - 1.722
Max Birefringence:
δ = 0.088
Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
and does not take into account mineral colouration.
Surface Relief:
Moderate
Dispersion:
Weak to distinct
Optical Extinction:
Y ⊥ laths; Z ‖ elongation. Positive elongation, parallel extinction.
Pleochroism:
Visible
Comments:
X = Y = pale brown, very pale yellow-green; Z = pale yellow-green.
Comments:
Pale yellow in transmitted light.
Chemistry of Sharpite
Mindat Formula:
Ca(UO2)3(CO3)4 · 3H2O
According to the single-crystal X-ray study (Plášil 2018), an idealized formula of sharpite is Ca(H2O)3[(UO2)3(CO3)3.6O0.2],where the content of (CO3) lies most probably within 4 > xCO3 > 3.5 apfu range.
According to the single-crystal X-ray study (Plášil 2018), an idealized formula of sharpite is Ca(H2O)3[(UO2)3(CO3)3.6O0.2],where the content of (CO3) lies most probably within 4 > xCO3 > 3.5 apfu range.
Crystallography of Sharpite
Crystal System:
Orthorhombic
Class (H-M):
mmm (2/m 2/m 2/m) - Dipyramidal
Space Group:
Cmcm
Cell Parameters:
a = 4.9032(4) Å, b = 15.6489(11) Å, c = 22.0414(18) Å
Ratio:
a:b:c = 0.313 : 1 : 1.408
Unit Cell V:
1691.2 ų
Z:
4
Morphology:
Occurs as crusts of thin, radiating fibers.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 4.497 Å | (100) |
| 3.910 Å | (48) |
| 7.82 Å | (40) |
| 5.34 Å | (35) |
| 2.996 Å | (33) |
| 11.02 Å | (30) |
| 6.37 Å | (28) |
Comments:
Shinkolobwe Mine, DR Congo. Data from Čejka (1984).
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] | |
| 47c : [Carbonates, phosphates, borates, nitrates] | |
| 47f : [Uranyl (U⁶⁺) minerals] |
Type Occurrence of Sharpite
General Appearance of Type Material:
Radially fibrous crust.
Place of Conservation of Type Material:
University of Liege, Liege, Belgium, 6280, 16905.
Geological Setting of Type Material:
Secondary mineral in oxide zone of hydrothermal uranium deposit.
Associated Minerals at Type Locality:
Reference:
Mélon, M.J. (1938) La sharpite, nouveau carbonate d'uranyle du Congo belge. Bulletin des Séances de l'Institut Royal Colonial Belge: 9: 333-336.
Other Language Names for Sharpite
Common Associates
Related Minerals - Strunz-mindat Grouping
| 5.EA.05 | UM1997-24-CO:CaCuHU | Ca2Cu(UO2)2(CO3)2O3 · 3H2O |
| 5.EA.10 | Urancalcarite | Ca(UO2)3(CO3)(OH)6 · 3H2O |
| 5.EA.15 | Wyartite | CaU5+(UO2)2(CO3)O4(OH) · 7H2O |
| 5.EA.20 | Oswaldpeetersite | (UO2)2(CO3)(OH)2 · 4H2O |
| 5.EA.25 | Roubaultite | Cu2(UO2)3(CO3)2O2(OH)2 · 4H2O |
| 5.EA.30 | Kamotoite-(Y) | Y2(UO2)4(CO3)3O4 · 14H2O |
Other Information
Notes:
Soluble in dilute acids with effervescence.
Radioactive.
Radioactive.
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 Sharpite
mindat.org URL:
https://www.mindat.org/min-3633.html
Please feel free to link to this page.
Please feel free to link to this page.
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External Links:
References for Sharpite
Localities for Sharpite
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.
DR Congo (TL) | |
| Deliens +3 other references |
France | |
| Mineralogical Society of America - ... +1 other reference |
| - (1998) |
Germany | |
| Aufschluss 69/ (7+8) +1 other reference |
Poland | |
| Eligiusz Szełęg collection (SEM/EDS identification) |
| pl.wikipedia.org (2006) |
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Shinkolobwe Mine, Shinkolobwe, Kambove Territory, Haut-Katanga, DR Congo