Weeksite
A valid IMA mineral species
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About Weeksite
Alice M. D. Weeks
Formula:
K2(UO2)2(Si5O13) · 4H2O
Colour:
Yellow
Lustre:
Waxy, Silky
Hardness:
1 - 2
Specific Gravity:
4.1
Crystal System:
Monoclinic
Name:
Named in 1960 by W. F. Osterbridge, Mortimer Hay Staatz, Robert Meyrowitz, and A. M. Plummer in honor of Alice Mary Dowse Weeks [August, 26, 1909 Sherborn, Massachusetts, USA - August 29, 1988 Bryn Mawr, Pennsylvania, USA], mineralogist for the United States Geological Survey and later professor of mineralogy, Temple University (Philadelphia, USA).
This page provides mineralogical data about Weeksite.
Unique Identifiers
Mindat ID:
4255
Long-form identifier:
mindat:1:1:4255:6
GUID
(UUID V4):
(UUID V4):
17646d92-bea6-4946-9f9a-48fc2afa2c20
IMA Classification of Weeksite
Approved
IMA Formula:
(K)2(UO2)2(Si5O13) · 4H2O
First published:
1960
Classification of Weeksite
9.AK.30
9 : SILICATES (Germanates)
A : Nesosilicates
K : Uranyl neso- and polysilicates
9 : SILICATES (Germanates)
A : Nesosilicates
K : Uranyl neso- and polysilicates
53.3.2.1
53 : NESOSILICATES Insular SiO4 Groups and Other Anions or Complex Cations
3 : Insular SiO4 Groups and Other Anions of Complex Cations with (UO2)
53 : NESOSILICATES Insular SiO4 Groups and Other Anions or Complex Cations
3 : Insular SiO4 Groups and Other Anions of Complex Cations with (UO2)
14.16.5
14 : Silicates not Containing Aluminum
16 : Silicates of U
14 : Silicates not Containing Aluminum
16 : Silicates of 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 |
|---|---|---|
| Wks | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Pronunciation of Weeksite
Pronunciation:
| Play | Recorded by | Country |
|---|---|---|
| Jolyon Ralph | United Kingdom |
Physical Properties of Weeksite
Waxy, Silky
Transparency:
Transparent, Translucent
Colour:
Yellow
Hardness:
1 - 2 on Mohs scale
Cleavage:
Distinct/Good
Two good prismatic cleavages noted.
Two good prismatic cleavages noted.
Density:
4.1 g/cm3 (Measured) 3.80 g/cm3 (Calculated)
Optical Data of Weeksite
Type:
Biaxial (-)
RI values:
nα = 1.596 nβ = 1.603 nγ = 1.606
2V:
Measured: 60° , Calculated: 66°
Max Birefringence:
δ = 0.010
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:
r < v weak
Pleochroism:
Strong
Comments:
X = colorless, Y = pale yellow-green, Z = yellow-green.
Chemistry of Weeksite
Mindat Formula:
K2(UO2)2(Si5O13) · 4H2O
Common Impurities:
Al,Fe,Ca,Ba,Na,C
Crystallography of Weeksite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
B2/m
Setting:
C2/m
Cell Parameters:
a = 14.26(2) Å, b = 35.88(10) Å, c = 14.20(2) Å
β = 111.578(3)°
β = 111.578(3)°
Ratio:
a:b:c = 0.397 : 1 : 0.396
Unit Cell V:
6,756.24 ų (Calculated from Unit Cell)
Z:
4
Twinning:
By two-fold rotation around [401].
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
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Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
Black Background | White Background
Perspective On | Perspective Off
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) |
|---|---|---|---|---|---|---|---|
| 0000839 | Weeksite | Stohl F V, Smith D K (1981) The crystal chemistry of the uranyl silicate minerals American Mineralogist 66 610-625 |  | 1981 | Anderson mine, Yavapai County, Arizona, USA | 0 | 293 |
| 0018760 | Weeksite | Fejfarova K, Plasil J, Yang H, Cejka J, Dusek M, Downs R T, Barkley M C, Skoda R (2012) Revision of the crystal structure and chemical formula of weeksite, K2(UO2)2(Si5O13)*4H2O American Mineralogist 97 750-754 | 2012 | Anderson mine, Arizona, USA | 0 | 293 | |
| 0005712 | Weeksite | Jackson J M, Burns P C (2001) A re-evaluation of the structure of weeksite, a uranyl silicate framework mineral The Canadian Mineralogist 39 187-195 | | 2001 | 0 | 293 | |
| 0018510 | Weeksite | Baturin S V (1985) Crystal-structure of weeksite Doklady Akademii Nauk SSSR 282 1132-1136 | 1985 | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 7.11 Å | (10) |
| 5.57 Å | (9) |
| 8.98 Å | (8) |
| 3.55 Å | (7) |
| 3.30 Å | (7) |
| 2.91 Å | (6) |
| 3.20 Å | (5) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] | |
| 47f : [Uranyl (U⁶⁺) minerals] |
Type Occurrence of Weeksite
General Appearance of Type Material:
Yellow radiating fibrous clusters
Place of Conservation of Type Material:
National Museum of Natural History (Smithsonian), Washington, D.C., USA, 128713, 115886, 121949.
Geological Setting of Type Material:
In opal veinlets and as replacements of pebbles in tuffaceous conglomerate.
Associated Minerals at Type Locality:
Reference:
Outerbridge W.F., Staatz, M. H., Meyrowitz, R., Pommer, A. M. (1960) Weeksite, a new uranium silicate from the Thomas Range, Juab Co., Utah. American Mineralogist: 45: 39-52.
Other Language Names for Weeksite
Common Associates
Associated Minerals Based on Photo Data:
| 14 photos of Weeksite associated with Carnotite | K2(UO2)2(VO4)2 · 3H2O |
| 11 photos of Weeksite associated with Autunite | Ca(UO2)2(PO4)2 · 10-12H2O |
| 9 photos of Weeksite associated with Chalcedony | SiO2 |
| 8 photos of Weeksite associated with Opal | SiO2 · nH2O |
| 6 photos of Weeksite associated with Quartz | SiO2 |
| 5 photos of Weeksite associated with Goethite | α-Fe3+O(OH) |
| 4 photos of Weeksite associated with Opal-AN | SiO2 · nH2O |
| 4 photos of Weeksite associated with Bluelizardite | Na7(UO2)(SO4)4Cl(H2O)2 |
| 4 photos of Weeksite associated with Becquerelite | Ca(UO2)6O4(OH)6 · 8H2O |
| 4 photos of Weeksite associated with Natrozippeite | Na5(UO2)8(SO4)4O5(OH)3 · 12H2O |
Related Minerals - Strunz-mindat Grouping
| 9.AK. | Orlite | Pb3(UO2)3(Si2O7)2 · 6H2O |
| 9.AK.05 | Soddyite | (UO2)2SiO4 · 2H2O |
| 9.AK.10 | Cuprosklodowskite | Cu(UO2)2(SiO3OH)2 · 6H2O |
| 9.AK.10 | Oursinite | Co(UO2)2(SiO3OH)2 · 6H2O |
| 9.AK.10 | Sklodowskite | Mg(UO2)2(SiO3OH)2 · 6H2O |
| 9.AK.15 | Boltwoodite | (K,Na)(UO2)(SiO3OH) · 1.5H2O |
| 9.AK.15 | Kasolite | Pb(UO2)(SiO4) · H2O |
| 9.AK.15 | Natroboltwoodite | Na(UO2)(SiO3OH) · H2O |
| 9.AK.15 | Parauranophane | Ca(UO2)2(SiO3OH)2 · 5H2O |
| 9.AK.15 | Uranophane | Ca(UO2)2(SiO3OH)2 · 5H2O |
| 9.AK.20 | Swamboite-(Nd) | Nd0.333[(UO2)(SiO3OH)](H2O)~2.5 |
| 9.AK.25 | Haiweeite | Ca(UO2)2[Si5O12(OH)2] · 6H2O |
| 9.AK.25 | Metahaiweeite | Ca(UO2)2Si6O15 · nH2O |
| 9.AK.30 | Coutinhoite | ThxBa(1-2x)(UO2)2Si5O13 · (H2O)1+y (0 < x < 0.5 and 0 < y < (2+x)) |
| 9.AK.35 | Magnioursilite | Mg4(UO2)4(Si2O5)5(OH)6 · 20H2O |
| 9.AK.35 | Calcioursilite | Ca4(UO2)4(Si2O5)5(OH)6 · 15H2O |
| 9.AK.40 | Uranosilite | UO3 · 7SiO2 |
Other Information
Health Risks:
Contains uranium. Always wash hands after handling. Do not lick or ingest. Store in an uninhabited area
Internet Links for Weeksite
mindat.org URL:
https://www.mindat.org/min-4255.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 Weeksite
Reference List:
Outerbridge, W. F., Staatz, M. H., Meyrowitz, R., Pommer, A. M. (1960) Weeksite, a new uranium silicate from the Thomas Range, Juab County, Utah. American Mineralogist, 45 (1-2) 39-52
(1962) International Mineralogical Association: Commission on New Minerals and Mineral Names. Mineralogical Magazine and Journal of the Mineralogical Society, 33 (258) 260-263 doi:10.1180/minmag.1962.033.258.09
Deliens, Michel (1977) Présence de weeksite aux Bois Noirs, massif du Forez (Loire) Bulletin de Minéralogie, 100 (5) 275 doi:10.3406/bulmi.1977.7149
Stohl, Frances V., Smith, Deane K. (1981) The crystal chemistry of the uranyl silicate minerals. American Mineralogist, 66 (5-6) 610-624
Biwer, Bruce M., Ebert, William L., Bates, John K. (1990) The Raman spectra of several uranyl-containing minerals using a microprobe. Journal of Nuclear Materials, 175 (3). 188-193 doi:10.1016/0022-3115(90)90205-2
Jackson, J. M., Burns, P. C. (2001) A re-evaluation of the structure of weeksite, a uranyl silicate framework mineral. The Canadian Mineralogist, 39 (1) 187-195 doi:10.2113/gscanmin.39.1.187
Jambor, John L., Roberts, Andrew C. (2001) New mineral names. American Mineralogist, 86 (9) 1112-1115
Burns, Peter C. (2005) U6+ minerals and inorganic compounds: insights into an expanded structural hierarchy of crystal structures. The Canadian Mineralogist, 43 (6) 1839-1894 doi:10.2113/gscanmin.43.6.1839
Frost, Ray L., Čejka, Jiří, Weier, Matt L., Martens, Wayde, Kloprogge, J. Theo (2006) A Raman and infrared spectroscopic study of the uranyl silicates—Weeksite, soddyite and haiweeite. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 64 (2) 308-315 doi:10.1016/j.saa.2005.07.028
Frost, Ray L., Čejka, Jiří, Weier, Matt L., Martens, Wayde (2006) A Raman and infrared spectroscopic study of the uranyl silicates—Weeksite, soddyite and haiweeite: Part 2. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 63 (2) 305-312 doi:10.1016/j.saa.2005.05.015
Localities for Weeksite
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 | |
| Brugger et al. (2003) +1 other reference |
Austria | |
| Brandstätter et al. (1987) +1 other reference |
Brazil | |
| Pires et al. (2014) |
| Bruno Gioia specimen +1 other reference |
| Revista Brasileira de Geociências 24 (1) +1 other reference |
| Fosfatos e Silicatos Secundários de ... | |
Chile | |
| According to Dr. Tony Kampf |
China | |
| Abudukeyumu et al. (2022) |
Czech Republic | |
| Pauliš P. et al. (Kutna Hora, issue 1) |
| Lapis 2002 (7/8) |
| Pauliš P. et al. (Kutna Hora, issue 1) |
Egypt | |
| 52 (2) +1 other reference |
France | |
| Georges Favreau collection |
Germany | |
| Walenta (1992) |
| Wittern (2001) |
| WITZKE (2018) |
Japan | |
| K. Watanabe (1976) |
Mexico | |
| Panczner (1987) |
| Panczner (1987) | |
| Panczner (1987) +2 other references | |
| Panczner (1987) | |
| Panczner (1987) | |
Namibia | |
| von Bezing (2007) |
Peru | |
| O'Connor et al. (2018) |
| Geological Association of Canada (2014) +1 other reference | |
Romania | |
| Hîrtopanu P. et al. (2004) |
USA | |
| Anthony et al. (1995) |
| Anthony et al. (1995) |
| Honea (1959) +2 other references |
| Van Nostrand Reinholt Press: 517. +2 other references |
| American Mineralogist (1970) |
| Nevada Bureau of Mines and Geology ... +1 other reference |
| NBMG files No. 50600003 +1 other reference | |
| Castor et al. (2004) | |
| - (2005) |
| |
| Castor et al. (2004) | |
| Castor et al. (2004) |
| Northrop et al. (1996) |
| Outerbridge et al. (1960) | |
| Northrop et al. (1996) | |
| AmMin.45:39 +2 other references |
| - (2005) |
| Smith (1991) | |
| Am.Min.: 45: 39-52 |
| King (n.d.) |
| Bullock (1981) |
| SLIDES OF THE FLUORSPAR | |
| Bullock (1981) | |
| Min.Rec.: 10: 271. +1 other reference |
| Bullock (1981) | |
| Collection of Alex Earl |
| Outerbridge et al. (1960) |
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