Clarkeite

Clarkeite

Bjertnes pegmatite, Krødsherad, Buskerud, Norway

Clarkeite, etc.

Bjertnes pegmatite, Krødsherad, Buskerud, Norway

Clarkeite, etc.

Fanny Gouge Mine, Micaville, Celo, Yancey County, North Carolina, USA

Clarkeite

Bjertnes pegmatite, Krødsherad, Buskerud, Norway

Clarkeite, etc.

Bjertnes pegmatite, Krødsherad, Buskerud, Norway

Clarkeite, etc.

Fanny Gouge Mine, Micaville, Celo, Yancey County, North Carolina, USA

Clarkeite

Bjertnes pegmatite, Krødsherad, Buskerud, Norway

Clarkeite, etc.

Bjertnes pegmatite, Krødsherad, Buskerud, Norway

About ClarkeiteHide

Frank Wigglesworth Clarke

Formula:

(Na,Ca,Pb)(UO₂)O(OH) · 0-1H₂O

Colour:

Dark red-brown, dark brown

Lustre:

Resinous, Waxy, Greasy

Hardness:

4 - 4½

Specific Gravity:

6.29 - 6.39

Crystal System:

Trigonal

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.

Type Locality:

ⓘ Deer Park No. 2 Mine, Penland, Mitchell County, North Carolina, USA

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."

Unique IdentifiersHide

IMA Classification of ClarkeiteHide

Classification of ClarkeiteHide

Mineral SymbolsHide

Physical Properties of ClarkeiteHide

Optical Data of ClarkeiteHide

Type:

Biaxial (-)

RI values:

n_α = 1.997 n_β = 2.098 n_γ = 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

Pleochroism:

Weak

Comments:

Orange and slightly deeper orange

Chemistry of ClarkeiteHide

Crystallography of ClarkeiteHide

Crystal StructureHide

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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)
0001902	Clarkeite	Finch R J, Ewing R C (1997) Clarkeite: New chemical and structural data American Mineralogist 82 607-619		1997		0	293

CIF Raw Data - click here to closedata_global _chemical_name_mineral 'Clarkeite' loop_ _publ_author_name 'Finch R J' 'Ewing R C' _journal_name_full 'American Mineralogist' _journal_volume 82 _journal_year 1997 _journal_page_first 607 _journal_page_last 619 _publ_section_title ; Clarkeite: New chemical and structural data ; _database_code_amcsd 0001902 _chemical_formula_sum 'U Na O4' _cell_length_a 3.954 _cell_length_b 3.954 _cell_length_c 17.660 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 120 _cell_volume 239.108 _exptl_crystal_density_diffrn 6.771 _symmetry_space_group_name_H-M 'R -3 m' loop_ _space_group_symop_operation_xyz 'x,y,z' '2/3+x,1/3+y,1/3+z' '1/3+x,2/3+y,2/3+z' 'x,x-y,z' '2/3+x,1/3+x-y,1/3+z' '1/3+x,2/3+x-y,2/3+z' 'y,x,-z' '2/3+y,1/3+x,1/3-z' '1/3+y,2/3+x,2/3-z' '-x+y,y,z' '2/3-x+y,1/3+y,1/3+z' '1/3-x+y,2/3+y,2/3+z' '-x,-x+y,-z' '2/3-x,1/3-x+y,1/3-z' '1/3-x,2/3-x+y,2/3-z' '-y,-x,z' '2/3-y,1/3-x,1/3+z' '1/3-y,2/3-x,2/3+z' 'x-y,-y,-z' '2/3+x-y,1/3-y,1/3-z' '1/3+x-y,2/3-y,2/3-z' 'y,-x+y,-z' '2/3+y,1/3-x+y,1/3-z' '1/3+y,2/3-x+y,2/3-z' '-x+y,-x,z' '2/3-x+y,1/3-x,1/3+z' '1/3-x+y,2/3-x,2/3+z' '-x,-y,-z' '2/3-x,1/3-y,1/3-z' '1/3-x,2/3-y,2/3-z' '-y,x-y,z' '2/3-y,1/3+x-y,1/3+z' '1/3-y,2/3+x-y,2/3+z' 'x-y,x,-z' '2/3+x-y,1/3+x,1/3-z' '1/3+x-y,2/3+x,2/3-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv U 0.00000 0.00000 0.00000 0.00367 Na 0.00000 0.00000 0.50000 0.00684 O1 0.00000 0.00000 0.10690 0.00532 O2 0.00000 0.00000 0.34880 0.00532

X-Ray Powder DiffractionHide

Geological EnvironmentHide

Type Occurrence of ClarkeiteHide

Synonyms of ClarkeiteHide

Other Language Names for ClarkeiteHide

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Related Minerals - Strunz-mindat GroupingHide

Fluorescence of ClarkeiteHide

Other InformationHide

Internet Links for ClarkeiteHide

References for ClarkeiteHide

Localities for ClarkeiteHide

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.

Locality ListHide

- 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.

Argentina
La Rioja Province Chilecito department Sañogasta ⓘ San Sebastián deposit	Angelelli (1984)
Brazil
Bahia ⓘ Lagoa Real uranium province	Pires et al. (2014)
Canada
Nova Scotia Cumberland Co. ⓘ McLean Point	Chatterjee (1977)
Czech Republic
Plzeň Region Tachov District Zadní Chodov ⓘ Zadní Chodov deposit (Hinterkotten deposit)	Pauliš et al. (2007)
Hungary
Baranya County Pécs District Kővágótöttös ⓘ Kővágószőlős Uranium Mine	Koch: Minerals of Hungary
India
Andhra Pradesh Nellore District ⓘ Jogipalle pegmatite	Singh et al. (2015)
Rajasthan ⓘ Ajmer District	American Mineralogist: 41: 127-133
Norway
Agder ⓘ Gjerstad	Neumann (1985)
Lindesnes Vigeland ⓘ Rymteland Feldspar Quarry	Sverdrup (1959)
Buskerud Krødsherad ⓘ Bjertnes pegmatite	Neumann (1985)
Nordland Narvik ⓘ Hundholmen	Husdal (2023)
Romania
Suceava County ⓘ Crucea	Hîrtopanu P. et al. (2004)
Ukraine
Zhytomyr Oblast Korosten Raion ⓘ Perzhanskoe ore field (Perga Be deposit)	Liventseva (n.d.)
USA
Alaska Yukon-Koyukuk Census Area Sheenjek Mining District ⓘ Sunaghun Creek Confluence Occurrence ?	- (2008)
Maine Oxford County Newry ⓘ Dunton Gem Quarry	King et al. (1994)
Stoneham ⓘ Lord Hill Quarry (Lord Hill Mine)	King et al. (1994)
New Hampshire Grafton County Grafton ⓘ Ruggles Mine	Frondel (1956) +1 other reference
Groton ⓘ Palermo No. 1 Mine ?	Not found at this locality: Frondel (1956) +1 other reference
Rockingham County Raymond ⓘ Blake-Welch Mines (Welch Mine; Mafera Mine)	Smith (2005)
North Carolina Mitchell County ⓘ Flat Rock Mine (Flat Rock pegmatite)	Rocks and Minerals
ⓘ Googrock Mine	Roger Howell Collection
Penland ⓘ Deer Park No. 2 Mine (TL)	Ross et al. (1931) +1 other reference
ⓘ Pink Mine	Rocks and Minerals
Spruce Pine ⓘ English Mine (English Knob Mine)	Smithsonian Institution Mineral ...
Greasy Creek Township ⓘ Wiseman Mine (Old Mart Wiseman Mine; Sullins-Wiseman Mine)	Rocks and Minerals
ⓘ McKinney Mine (Power Mill Creek Mine)	www.excaliburmineral.com
Yancey County Celo Micaville ⓘ Fanny Gouge Mine	American Mineralogist +1 other reference
Crabtree Creek ⓘ Carolina Mineral Company No. 20 Mine (Old 20 Mine)	Rocks and Minerals