Help mindat.org|Log In|Register|
Home PageMindat NewsThe Mindat ManualHistory of MindatCopyright StatusManagement TeamContact UsAdvertise on Mindat
Donate to MindatSponsor a PageSponsored PagesTop Available PagesMindat AdvertisersAdvertise on MindatThe Mindat Store
Minerals by PropertiesMinerals by ChemistryRandom MineralSearch by minIDLocalities Near MeSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
Keyword(s):
 
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportAdd Glossary Item
StatisticsMember ListBooks & MagazinesMineral Shows & EventsThe Mindat DirectoryHow to Link to MindatDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day Gallery

Clarkeite

This page is currently not sponsored. Click here to sponsor this page.
Frank Wigglesworth Clarke
Formula:
(Na,Ca,Pb)(UO2)O(OH) · 0-1H2O
System:
Trigonal
Colour:
Dark red-brown, dark ...
Hardness:
4 - 4½
Name:
Named in 1931 by Clarence S. Ross, Edward P. Henderson, and Eugene Waldemar Posnjak in honor of Frank Wigglesworth Clarke [March 19, 1847 Boston, Massachusetts, USA - May 23, 1931 Washington, DC, USA], American mineral chemist, and former Chief Chemist of the U.S. Geological Survey. Clarke studied the composition of the Earth's crust and the unit of measure, the clarke, was named as a reference to the local enrichment of a chemical component relative to an average value for the chemistry of the crust.
Clarkeite is a waxy to resinous dark brown replacement of uraninite. It is very uncommon, but is frequently misidentified with brown gummite that is dominated by schoepite-group minerals. Frondel (1956) warned: "Clarkeite is best identified by its X-ray powder pattern. It is indistinguishable from the dark brown types of oxidized uraninite ... and from dense brown types of fourmarierite and vandendriesscheite."

Classification of Clarkeite

Valid - first described prior to 1959 (pre-IMA) - "Grandfathered"
4.GC.05

4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
G : Uranyl Hydroxides
C : With additional cations; with mainly UO2(O,OH)6 hexagonal polyhedra
5.4.1.1

5 : OXIDES CONTAINING URANIUM OR THORIUM
4 : AX2O7·xH2O
7.16.32

7 : Oxides and Hydroxides
16 : Oxides of U
mindat.org URL:
http://www.mindat.org/min-1059.html
Please feel free to link to this page.

Type Occurrence of Clarkeite

Year of Discovery:
1931

Physical Properties of Clarkeite

Resinous, Waxy, Greasy
Diaphaneity (Transparency):
Translucent
Colour:
Dark red-brown, dark brown
Streak:
Yellow-brown
Hardness (Mohs):
4 - 4½
Fracture:
Conchoidal, Sub-Conchoidal
Density:
6.39 g/cm3 (Measured)    

Crystallography of Clarkeite

Crystal System:
Trigonal
Cell Parameters:
a = 3.954Å, c = 17.660Å
Ratio:
a:c = 1 : 4.466
Unit Cell Volume:
V 239.11 ų (Calculated from Unit Cell)
Z:
3
Morphology:
Massive, dense.
X-Ray Powder Diffraction Data:
d-spacingIntensity
5.903 (64)
3.365 (56)
3.195 (100)
2.945 (28)
2.707 (34)
1.977 (33)
1.8742 (19)
1.8554 (19)
1.6807 (14)
1.6410 (23)
Comments:
AM 82, p. 615; JCPDS 8-315 has extraneous and differing d-values.

Optical Data of Clarkeite

Type:
Biaxial (-)
RI values:
nα = 1.997 nβ = 2.098 nγ = 2.108
2V:
Measured: 30° to 50°, Calculated: 32°
Birefringence:
0.111
Max Birefringence:
δ = 0.111
Image shows birefringence interference colour range (at 30µm thickness) and does not take into account mineral colouration.
Surface Relief:
Very High
Dispersion:
relatively weak

Chemical Properties of Clarkeite

Formula:
(Na,Ca,Pb)(UO2)O(OH) · 0-1H2O
Essential elements:
All elements listed in formula:

Relationship of Clarkeite to other Species

4.GC.10Umohoite(UO2)MoO4 · 2H2O
4.GC.15SpriggitePb3(UO2)6O8(OH)2 · 3H2O
7.16.1UraniniteUO2
7.16.2Schoepite(UO2)8O2(OH)12 · 12H2O
7.16.3ParaschoepiteUO3 · 2H2O
7.16.4MetaschoepiteUO3 · 1-2H2O
7.16.5MetastudtiteUO4 · 2H2O
7.16.6Studtite[(UO2)(O2)(H2O)2] · H2O
7.16.7IanthiniteU4+(UO2)5O7 · 10H2O
7.16.8CompreignaciteK2(UO2)6O4(OH)6 · 7H2O
7.16.9VandenbrandeiteCu(UO2)(OH)4
7.16.10RoubaultiteCu2(UO2)3(OH)10 · 5H2O
7.16.11BecquereliteCa(UO2)6O4(OH)6 · 8H2O
7.16.12RameauiteK2Ca(UO2)6(OH)16 · H2O
7.16.13AgrinieriteK2(Ca,Sr)(UO2)3O3(OH)2·5H2O
7.16.14ProtasiteBa(UO2)3O3(OH)2 · 3H2O
7.16.15BillietiteBa(UO2)6O4(OH)6 · 4-8H2O
7.16.16BauranoiteBa(UO2)2(OH)6 · 1-2H2O
7.16.17Metacalciouranoite(Ca,Ba,Pb,K2)U2O7 · 2H2O
7.16.18Calciouranoite(Ca,Ba,Pb)U2O7 · 5H2O
7.16.19OrthobranneriteU4+U6+Ti4O12(OH)2
7.16.20Thorutite(Th,U,Ca)Ti2(O,OH)6
7.16.21Davidite-(La)(La,Ce)(Y,U,Fe)(Ti,Fe)20(O,OH)38
7.16.22Davidite-(Ce)(Ce,La)(Y,U,Fe)(Ti,Fe)20(O,OH)38
7.16.23Brannerite(U4+,REE,Th,Ca)(Ti,Fe3+,Nb)2(O,OH)6
7.16.24FourmarieritePb(UO2)4O3(OH)4 · 4H2O
7.16.25RichetitePb(UO2)4O5 · 4H2O
7.16.26CuritePb3(UO2)8O8(OH)6 · 3H2O
7.16.27MasuyitePb(UO2)3O3(OH)2 · 3H2O
7.16.28VandendriesscheitePbU7O22 · 12H2O
7.16.29MetavandendriesscheitePbU7O22 · nH2O n < 12
7.16.30SayritePb2(UO2)5O6(OH)2 · 4H2O
7.16.31Wölsendorfite(Pb,Ca)U2O7 · 2H2O
7.16.33UranosphaeriteBi(UO2)O2(OH)

Other Names for Clarkeite

Name in Other Languages:
German:Clarkeit
Simplified Chinese:水钠铀矿
Spanish:Clarkeita

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.

References for Clarkeite

Reference List:
Ross, Henderson, and Posnjak (1931), American Mineralogist: 16: 213.

Palache, Charles, Harry Berman & Clifford Frondel (1944), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana Yale University 1837-1892, Volume I: Elements, Sulfides, Sulfosalts, Oxides. John Wiley and Sons, Inc., New York. 7th edition, revised and enlarged: 624-625.

Frondel, Clifford, 1956, Systematic Mineralogy of Uranium and Thorium, USGS Bulletin 1064, pp. 400.

Finch, Robert J. and Ewing, Rodney C., 1997, Clarkeite: New Chemical and Structural Data, American Mineralogist, 82: 607-619.

Finch, R.J. and R.C. Ewing (1997), Clarkeite: New chemical and structural data: American Mineralogist: 82: 607-619.

Kubatko, Karrie-Ann, Katheryn Helean, Alexandra Navrotsky, and Peter C. Burns (2006), Thermodynamics of uranyl minerals: Enthalpies of formation of uranyl oxide hydrates: American Mineralogist: 91: 658-666.

Internet Links for Clarkeite

Localities for Clarkeite

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.
(TL) indicates type locality for a valid mineral species. (FRL) indicates first recorded locality for everything else. ? indicates mineral may be doubtful at this locality. All other localities listed without reference should be considered as uncertain and unproven until references can be found.
Canada
 
  • Nova Scotia
    • Cumberland Co.
A.K. Chatterjee, "Uranium Mineralization at McLean Point, Cumberland County", Nova Scotia Dept. Mines Report 77-1, 1977.
Czech Republic
 
  • Bohemia (Böhmen; Boehmen)
    • Plzeň Region
      • Planá u Mariánských Lázní (Plan)
Pauliš P., Kopecký S., Černý P. 2007: Uranové minerály České Republiky a jejich naleziště. 1. část. (Kutna Hora, issue 1)
Hungary
 
  • Baranya Co.
    • Mecsek Mts
Koch: Minerals of Hungary, 1985
India
 
  • Rajasthan (Rajputana)
    • Ajmer Division
American Mineralogist: 41: 127-133
Norway
 
  • Aust-Agder
Neumann, H. (1985): Norges Mineraler. Norges geologiske Undersøkelse Skrifter 68, p 90
  • Buskerud
    • Krødsherad
      • Krøderen Lake
Neumann, H. (1985): Norges Mineraler. Norges geologiske Undersøkelse Skrifter 68, pp. 89-90
  • Vest-Agder
    • Lindesnes
      • Vigeland
Sverdrup, T. L. (1959): The pegmatite dyke at Rømteland. Norges Geologiske Undersøkelse 211 (Årbok 1959): 124-196
USA
 
  • Alaska
    • Yukon-Koyukuk Borough
      • Sheenjek District
U.S. Geological Survey, 2008, Alaska Resource Data File (ARDF): U.S. Geological Survey Open-File Report 2008-1225.
  • Maine
    • Oxford Co.
      • Newry
Not found according to King, V. T., 1994, Mineralogy of Maine, Descriptive Mineralogy, v. 1
      • Stoneham
Not found according to King & Foord, 1994. Mineralogy of Maine, V. 1.
  • New Hampshire
    • Grafton Co.
      • Grafton
Discredited by Clifford Frondel (1956) Mineral Composition of Gummite, American Mineralogist 41:539-568.; Rocks & Minerals (2005) 80:242-261 New Hampshire Mineral Locality Index
      • Groton
Not found at this locality: Frondel (1956); Foord et al. (1997), Korzeb et al (1997).
    • Rockingham Co.
      • Raymond
Rocks & Minerals (2005) 80:242-261 New Hampshire Mineral Locality Index
  • North Carolina
    • Mitchell Co.
Rocks and Minerals, Sep-Oct,2004
Roger Howell Collection
Rocks and Minerals,Sep-Oct,2004
      • Spruce Pine District
        • Penland
Ross, Henderson, and Posnjak (1931), American Mineralogist: 16: 213.; Arthur Roe and John S. White, Jr. (1976) A Catalog of the Type Specimens in the Mineral Collection, National Museum of Natural History
        • Spruce Pine
          • Greasy Creek Township
Rocks and Minerals,Sep-Oct,2004
www.excaliburmineral.com
Rocks and Minerals,Sep-Oct,2004
    • Yancey Co.
      • Spruce Pine District
        • Celo
          • Micaville
U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.; American Mineralogist, Volume 82, pages 607–619, 1997
Mineral and/or Locality  
Mindat.org is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2015, except where stated. Mindat.org relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: May 25, 2015 04:41:57 Page generated: May 18, 2015 07:37:28