Crookesite
A valid IMA mineral species - grandfathered
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About Crookesite
Formula:
Cu7(Tl, Ag)Se4
Formely considered (Cu,Tl,Ag)2Se.
Colour:
Lead Grey
Lustre:
Metallic
Hardness:
2½ - 3
Specific Gravity:
6.90
Crystal System:
Tetragonal
Name:
Named in honor of Sir William Crookes (17 June 1832, London, England - 4 April 1919, London, England), chemist and physicist. He worked on spectroscopy, and used that technology to discover thallium in 1861.
Type Locality:
This page provides mineralogical data about Crookesite.
Unique Identifiers
Mindat ID:
1159
Long-form identifier:
mindat:1:1:1159:0
GUID
(UUID V4):
(UUID V4):
dbf87b55-b5ad-4889-855a-4bf7ff096787
IMA Classification of Crookesite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
Cu7TlSe4
First published:
1867
Classification of Crookesite
2.BD.50
2 : SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulfantimonites, sulfbismuthites, etc.)
B : Metal Sulfides, M: S > 1: 1 (mainly 2: 1)
D : With Hg, Tl
2 : SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulfantimonites, sulfbismuthites, etc.)
B : Metal Sulfides, M: S > 1: 1 (mainly 2: 1)
D : With Hg, Tl
2.4.12.1
2 : SULFIDES
4 : AmBnXp, with (m+n):p = 2:1
2 : SULFIDES
4 : AmBnXp, with (m+n):p = 2:1
3.5.12
3 : Sulphides, Selenides, Tellurides, Arsenides and Bismuthides (except the arsenides, antimonides and bismuthides of Cu, Ag and Au, which are included in Section 1)
5 : Sulphides etc. of Hg and Tl
3 : Sulphides, Selenides, Tellurides, Arsenides and Bismuthides (except the arsenides, antimonides and bismuthides of Cu, Ag and Au, which are included in Section 1)
5 : Sulphides etc. of Hg and Tl
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
Symbol | Source | Reference |
---|---|---|
Crk | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Crk | The Canadian Mineralogist (2019) | The Canadian Mineralogist (2019) The Canadian Mineralogist list of symbols for rock- and ore-forming minerals (December 30, 2019). download |
Physical Properties of Crookesite
Metallic
Transparency:
Opaque
Colour:
Lead Grey
Hardness:
2½ - 3 on Mohs scale
Hardness:
VHN100=92 - 123 kg/mm2 - Vickers
Tenacity:
Brittle
Cleavage:
Distinct/Good
Two at right angles
Two at right angles
Density:
6.90 g/cm3 (Measured) 7.443 g/cm3 (Calculated)
Optical Data of Crookesite
Anisotropism:
Weak but distinct in brownish tones
Reflectivity:
Wavelength | R1 | R2 |
---|---|---|
400nm | 33.6% | 35.9% |
420nm | 33.3% | 35.8% |
440nm | 32.7% | 35.8% |
460nm | 32.4% | 35.7% |
480nm | 32.5% | 35.6% |
500nm | 32.8% | 35.3% |
520nm | 33.1% | 35.1% |
540nm | 33.1% | 34.8% |
560nm | 33.0% | 34.7% |
580nm | 32.7% | 34.6% |
600nm | 32.6% | 34.7% |
620nm | 32.4% | 35.0% |
640nm | 32.2% | 35.2% |
660nm | 31.9% | 35.2% |
680nm | 31.6% | 35.3% |
700nm | 31.2% | 35.3% |
Graph shows reflectance levels at different wavelengths (in nm). Top of box is 100%. Peak reflectance is 35.9%.
R1 shown in black, R2 shown in red
Chemistry of Crookesite
Mindat Formula:
Cu7(Tl, Ag)Se4
Formely considered (Cu,Tl,Ag)2Se.
Formely considered (Cu,Tl,Ag)2Se.
Elements listed:
Common Impurities:
Fe
Crystallography of Crookesite
Crystal System:
Tetragonal
Cell Parameters:
a = 10.435 Å, c = 3.954 Å
Ratio:
a:c = 1 : 0.379
Unit Cell V:
430.55 ų (Calculated from Unit Cell)
Z:
2
Morphology:
Disseminated specks and in veinlets.
Comment:
Point Group: 4/m, 4, or 4 ; Space Group: I4/m, I4, or I4.
Crystal Structure
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Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
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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) |
---|---|---|---|---|---|---|---|
0013691 | Crookesite | Eriksson L, Werner P E, Berger R, Meerschaut A (1991) Structure refinement of TlCu7Se4 from X-ray powder profile data Journal of Solid State Chemistry 90 61-68 | 1991 | synthetic | 0 | 293 | |
0013692 | Crookesite | Eriksson L, Werner P E, Berger R, Meerschaut A (1991) Structure refinement of TlCu7Se4 from X-ray powder profile data Journal of Solid State Chemistry 90 61-68 | 1991 | synthetic | 0 | 293 | |
0013693 | Crookesite | Eriksson L, Werner P E, Berger R, Meerschaut A (1991) Structure refinement of TlCu7Se4 from X-ray powder profile data Journal of Solid State Chemistry 90 61-68 | 1991 | Skrikerum mine, Sweden | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
d-spacing | Intensity |
---|---|
3.29 Å | (100) |
2.59 Å | (100) |
3.00 Å | (80) |
2.11 Å | (50) |
1.833 Å | (40) |
1.779 Å | (40) |
2.32 Å | (30) |
Geological Environment
Paragenetic Mode(s):
Paragenetic Mode | Earliest Age (Ga) |
---|---|
Near-surface Processes | |
23 : Subaerial aqueous alteration by non-redox-sensitive fluids (see also #47) | |
High-𝑇 alteration and/or metamorphism | |
33 : Minerals deposited by hydrothermal metal-rich fluids (see also [#12]) |
Type Occurrence of Crookesite
General Appearance of Type Material:
As finely divided, disseminated specks.
Geological Setting of Type Material:
Hydrothermal deposits
Associated Minerals at Type Locality:
Reference:
Nordenskiöld, A.E. (1867) Sur les minéraux sélénifères et thallifères de Skrikerum. Bulletin Mensuel de la Société Chimique de Paris: 7: 409-414.
Other Language Names for Crookesite
Common Associates
Associated Minerals Based on Photo Data:
12 photos of Crookesite associated with Calcite | CaCO3 |
8 photos of Crookesite associated with Bukovite | (Cu3Fe)Σ4Tl2Se4 |
4 photos of Crookesite associated with Klockmannite | CuSe |
2 photos of Crookesite associated with Biotite | K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
1 photo of Crookesite associated with Berzelianite | Cu2-xSe (x ≈ 0.12) |
1 photo of Crookesite associated with Athabascaite | Cu5Se4 |
Related Minerals - Strunz-mindat Grouping
2.BD. | UM2004-33-S:AgCuHgSe | (Ag,Cu)8Hg3(S,Se)7 |
2.BD. | Vrančiceite | Cu10Hg3S8 |
2.BD.05 | Imiterite | Ag2HgS2 |
2.BD.10 | Gortdrumite | Cu24Fe2Hg9S23 |
2.BD.15 | Balkanite | Cu9Ag5HgS8 |
2.BD.15 | Danielsite | (Cu,Ag)14HgS8 |
2.BD.20 | Donharrisite | Ni3HgS3 |
2.BD.25 | Carlinite | Tl2S |
2.BD.30 | Bukovite | (Cu3Fe)Σ4Tl2Se4 |
2.BD.30 | Murunskite | K2(Cu,Fe)4S4 |
2.BD.30 | Thalcusite | Tl2Cu3FeS4 |
2.BD.35 | Rohaite | (Tl,Pb,K)2Cu8.7Sb2S4 |
2.BD.40 | Chalcothallite | Tl2(Cu,Fe)6SbS4 |
2.BD.45 | Sabatierite | TlCu6Se4 |
2.BD.55 | Brodtkorbite | Cu2HgSe2 |
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 Crookesite
mindat.org URL:
https://www.mindat.org/min-1159.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Crookesite
Reference List:
Earley, J. W. (1950) Description and synthesis of the selenide minerals. American Mineralogist, 35 (5-6) 337-364
Ramdohr, Paul (1969) The Ore Minerals and their Intergrowths. Pergamon Press, Oxford. 1174pp. doi:10.1016/c2013-0-10027-x
Jambor, John L., Burke, Ernst A. J. (1989) New Mineral Names. American Mineralogist, 74 (11-12) 1399-1404
Localities for Crookesite
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).
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.
All localities listed without proper references should be considered as questionable.
Argentina | |
| Paar et al. (2002) +2 other references |
Armenia | |
Khachaturyan (1957) | |
Canada | |
| Mineralogical Society of America - ... +1 other reference |
China | |
| Yanjing Chen et al. (2007) |
Zhao et al. (1999) | |
Czech Republic | |
| Škácha et al. (2017) |
| Kvaček +1 other reference |
| Vavřín +2 other references |
Kvaček (1979) | |
France | |
| Agrinier et al. (1967) |
Germany | |
| Weiß (1990) |
| Weiß (1990) |
| Forster et al. (2004) |
Sweden (TL) | |
| Am Min 35 (1950) +2 other references |
Switzerland | |
| Stalder et al. (1998) |
| Stalder et al. (1998) |
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Skrikerum Mine, Valdemarsvik, Östergötland County, Sweden