Cornetite
A valid IMA mineral species - grandfathered
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About Cornetite
Formula:
Cu3(PO4)(OH)3
Colour:
Dark blue to green-blue; green-blue in transmitted light.
Lustre:
Vitreous
Hardness:
4½
Specific Gravity:
4.10
Crystal System:
Orthorhombic
Name:
Named in honor of Mr. Jules Cornet (La Louvière, Belgium, March 4, 1865 - Mons, Belgium, May 17, 1929), a Belgian geologist. He prospected in the Congo and particularly in Katanga where he discovered its immense mineral wealth.
Cornetite was the first new mineral discovered in Congo.
Cornetite was the first new mineral discovered in Congo.
Type Locality:
This page provides mineralogical data about Cornetite.
Unique Identifiers
Mindat ID:
1131
Long-form identifier:
mindat:1:1:1131:6
GUID
(UUID V4):
(UUID V4):
534e7e3e-45b9-4456-af35-c4599c184437
IMA Classification of Cornetite
Approved, 'Grandfathered' (first described prior to 1959)
Classification of Cornetite
8.BE.15
8 : PHOSPHATES, ARSENATES, VANADATES
B : Phosphates, etc., with additional anions, without H2O
E : With only medium-sized cations, (OH, etc.):RO4 > 2:1
8 : PHOSPHATES, ARSENATES, VANADATES
B : Phosphates, etc., with additional anions, without H2O
E : With only medium-sized cations, (OH, etc.):RO4 > 2:1
41.3.2.1
41 : ANHYDROUS PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
3 : (AB)3(XO4)Zq
41 : ANHYDROUS PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
3 : (AB)3(XO4)Zq
19.2.2
19 : Phosphates
2 : Phosphates of Cu
19 : Phosphates
2 : Phosphates of Cu
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 |
---|---|---|
Cne | 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 Cornetite
Pronunciation:
Play | Recorded by | Country |
---|---|---|
Jolyon Ralph | United Kingdom |
Physical Properties of Cornetite
Vitreous
Transparency:
Transparent, Translucent
Colour:
Dark blue to green-blue; green-blue in transmitted light.
Comment:
May exhibit colour zoning in shades of green-blue.
Hardness:
4½ on Mohs scale
Cleavage:
None Observed
Density:
4.10 g/cm3 (Measured) 4.14 g/cm3 (Calculated)
Optical Data of Cornetite
Type:
Biaxial (-)
RI values:
nα = 1.765 nβ = 1.810 nγ = 1.820
2V:
Measured: 33° , Calculated: 48°
Max Birefringence:
δ = 0.055
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:
Very High
Dispersion:
none
Optical Extinction:
X = b; Y = a; Z = c.
Pleochroism:
Non-pleochroic
Chemistry of Cornetite
Mindat Formula:
Cu3(PO4)(OH)3
Elements listed:
Common Impurities:
Co
Crystallography of Cornetite
Crystal System:
Orthorhombic
Class (H-M):
mmm (2/m 2/m 2/m) - Dipyramidal
Space Group:
Pbca
Cell Parameters:
a = 10.88 Å, b = 14.1 Å, c = 7.11 Å
Ratio:
a:b:c = 0.772 : 1 : 0.504
Unit Cell V:
1,090.73 ų (Calculated from Unit Cell)
Morphology:
Crystals short prismatic [001] to equant. Face {210} commonly rounded. May also show large {021}, {221}. Crusts of minute crystals.
Twinning:
Reported on {h0l}.
Crystal Structure
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Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
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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) |
---|---|---|---|---|---|---|---|
0014624 | Cornetite | Eby R K, Hawthorne F C (1989) Cornetite: modulated densely-packed Cu2+ oxysalt Mineralogy and Petrology 40 127-136 | 1989 | Mine de L'Etoile, Katanga, Zaire | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
d-spacing | Intensity |
---|---|
5.07 Å | (60) |
5.48 Å | (50) |
4.55 Å | (30) |
4.29 Å | (90) |
3.68 Å | (70) |
3.17 Å | (80) |
3.04 Å | (100) |
2.95 Å | (50) |
2.74 Å | (30) |
2.54 Å | (30) |
2.44 Å | (30) |
2.15 Å | (30) |
2.06 Å | (70) |
1.574 Å | (40) |
1.545 Å | (40) |
1.509 Å | (30) |
Comments:
Bwana Mkubwa, Zambia. Data from Berry (1950).
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] |
Type Occurrence of Cornetite
General Appearance of Type Material:
Blue crystals, either isolated or grouped, on sandstone. Square prisms with ocathedral terminations.
Place of Conservation of Type Material:
Laboratory of Mineralogy, University of Liège, Belgium, 9.130 and 9.133.
Geological Setting of Type Material:
Oxidized zone of a hydrothermal copper deposit.
Associated Minerals at Type Locality:
Other Language Names for Cornetite
Common Associates
Associated Minerals Based on Photo Data:
124 photos of Cornetite associated with Malachite | Cu2(CO3)(OH)2 |
87 photos of Cornetite associated with Chrysocolla | Cu2-xAlx(H2-xSi2O5)(OH)4 · nH2O, x < 1 |
44 photos of Cornetite associated with Heterogenite | Co3+O(OH) |
34 photos of Cornetite associated with Pseudomalachite | Cu5(PO4)2(OH)4 |
22 photos of Cornetite associated with Libethenite | Cu2(PO4)(OH) |
2 photos of Cornetite associated with Duhamelite | (Pb,Bi,Ca)Cu(VO4)(OH,O) |
2 photos of Cornetite associated with Khorixasite | (Bi0.67◻0.33)Cu(VO4)(OH) |
1 photo of Cornetite associated with Mottramite | PbCu(VO4)(OH) |
1 photo of Cornetite associated with Sandstone |
Related Minerals - Strunz-mindat Grouping
8.BE.05 | Augelite | Al2(PO4)(OH)3 |
8.BE.10 | Grattarolaite | Fe3+3(PO4)O3 |
8.BE.20 | Clinoclase | Cu3(AsO4)(OH)3 |
8.BE.25 | Arhbarite | Cu2Mg(AsO4)(OH)3 |
8.BE.25 | Gilmarite | Cu3(AsO4)(OH)3 |
8.BE.30 | Allactite | Mn2+7(AsO4)2(OH)8 |
8.BE.30 | Flinkite | Mn2+2Mn3+(AsO4)(OH)4 |
8.BE.30 | Raadeite | Mg7(PO4)2(OH)8 |
8.BE.30 | Argandite | Mn7(VO4)2(OH)8 |
8.BE.35 | Chlorophoenicite | (Mn,Mg)3Zn2(AsO4)(OH,O)6 |
8.BE.35 | Magnesiochlorophoenicite | (Mg,Mn)3Zn2(AsO4)(OH,O)6 |
8.BE.35 | Mineral E (of Dunn, et. al., 1982) | |
8.BE.40 | Gerdtremmelite | (Zn,Fe)(Al,Fe)2(AsO4)(OH)5 |
8.BE.45 | Dixenite | CuMn2+14Fe2+(SiO4)2(As5+O4)(As3+O3)5(OH)6 |
8.BE.45 | Hematolite | (Mn,Mg,Al,Fe3+)15(As5+O4)2(As3+O3)(OH)23 |
8.BE.45 | Kraisslite | Zn3(Mn,Mg)25(Fe3+,Al)(As3+O3)2[(Si,As5+)O4]10(OH)16 |
8.BE.45 | Mcgovernite | Mn19Zn3(AsO4)3(AsO3)(SiO4)3(OH)21 |
8.BE.45 | Arakiite | (Zn,Mn2+)(Mn2+,Mg)12(Fe3+,Al)2(As5+O4)2(As3+O3)(OH)23 |
8.BE.45 | Turtmannite | (Mn,Mg)22.5Mg3-3x((V5+,As5+)O4)3(As3+O3)x(SiO4)3O5-5x(OH)20+x |
8.BE.45 | Carlfrancisite | Mn2+3(Mn2+,Mg,Fe3+,Al)42[As3+O3]2(As5+O4)4[(Si,As5+)O4]6[(As5+,Si)O4]2(OH)42 |
8.BE.50 | Synadelphite | Mn2+9(As5+O4)2(As3+O3)(OH)9 · 2H2O |
8.BE.55 | Holdenite | (Mn2+,Mg)6Zn3(AsO4)2(SiO4)(OH)8 |
8.BE.60 | Kolicite | Mn2+7Zn4(AsO4)2(SiO4)2(OH)8 |
8.BE.65 | Sabelliite | (Cu,Zn)2Zn(AsO4,SbO4)(OH)3 |
8.BE.70 | Jarosewichite | Mn2+3Mn3+(AsO4)(OH)6 |
8.BE.75 | Theisite | Cu5Zn5(AsO4,SbO4)2(OH)14 |
8.BE.80 | Coparsite | Cu4(AsO4,VO4)O2Cl |
8.BE.85 | Waterhouseite | Mn2+7(PO4)2(OH)8 |
8.BE.90 | Vasilseverginite | Cu9O4(AsO4)2(SO4)2 |
Other Information
Notes:
Soluble in cold HCl.
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 Cornetite
mindat.org URL:
https://www.mindat.org/min-1131.html
Please feel free to link to this page.
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External Links:
References for Cornetite
Reference List:
Richmond, Wallace E. (1940) Crystal chemistry of the phosphates, arsenates and vanadates of the type A2XO4(Z) American Mineralogist, 25 (7) 441-479
Frost, Ray L., Williams, Peter A., Martens, Wayde, Kloprogge, J. Theo, Leverett, Peter (2002) Raman spectroscopy of the basic copper phosphate minerals cornetite, libethenite, pseudomalachite, reichenbachite and ludjibaite. Journal of Raman Spectroscopy, 33 (4). 260-263 doi:10.1002/jrs.850
Localities for Cornetite
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.
Australia | |
| Museum Victoria Mineralogy Collection |
| Vera Munro-Smith (2006) +1 other reference |
Crane et al. (2001) | |
| Sorrell (n.d.) |
| Kim Macdonald |
Chile | |
| C. Lemanski collection (7198 & 7201CL) |
| maurizio dini collection - analysed ... |
| C. Ruiz Fuller/F. Peebles (1988) |
| samples analysed by Dr. Hubert Putz |
DR Congo | |
| Museum of Victoria specimen No. M ... +1 other reference |
| Lapis 17 (3) |
De Bondt (n.d.) | |
| |
| Palache et al. (1951) +1 other reference |
Mambwe et al. (Ruashi Cu-Co Deposit) | |
| L. Kruszewski collection |
| Lapis 17 (3) |
| Wilson (2018) |
Germany | |
| Weiß (1990) |
Weiß (1990) | |
Morocco | |
| Georges Favreau collection |
Namibia | |
| SEM-EDS analysed by Georges Favreau (photo ID 1214009) |
Russia | |
| Gongalsky et al. (2019) |
South Africa | |
| Thomas Kleser Collection +2 other references |
Spain | |
| Bocamina (4) |
| Calvo Rebollar et al. (2024) |
| Joan Abella i Creus (Joanabellacreus@gmail.com) |
USA | |
| Khin (1970) +1 other reference |
| Mineralogy of Arizona |
| Eckel et al. (1997) |
| Palache et al. (1951) +1 other reference |
| Castor et al. (2004) |
Castor et al. (2004) | |
Palache et al. (1951) | |
| Palache et al. (1951) +1 other reference |
| NBMG Bull 70 Geology and Mineral ... |
| Northrop et al. (1996) |
Zambia | |
| Palache et al. (1951) |
| MacIntyre (2019) |
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L'Etoile du Congo Mine, Lubumbashi, Haut-Katanga, DR Congo