Aurichalcite
A valid IMA mineral species - grandfathered
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About Aurichalcite
Formula:
(Zn,Cu)5(CO3)2(OH)6
Zn:Cu ratio is about 5:2, but may approach 2:1.
Colour:
Pale green, sky blue, or greenish blue; colourless to light shades of blue or green in transmitted light
Lustre:
Silky, Pearly
Hardness:
1 - 2
Specific Gravity:
3.96
Crystal System:
Monoclinic
Name:
A sage noted that the Aurichalcum (Latinized version of the Greek ορείχαλκος - "mountain copper") of the ancients was "cuivre de Corinthe", yellow copper or brass; in 1839, Th. Böttger named the mineral accordingly, in allusion to its copper and zinc content, the constituents of brass.
A secondary mineral in copper and zinc deposits, aurichalcite is typically found as blue or green crusts or mats of tiny acicular crystals, often as feathery, tufted, druzes; more rarely it is found as columnar crystal aggregates or crusts of either lamellar aggregates or as granular aggregates.
Unique Identifiers
Mindat ID:
422
Long-form identifier:
mindat:1:1:422:4
IMA Classification of Aurichalcite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
(Zn2+,Cu2+)5(CO3)2(OH)6
Classification of Aurichalcite
5.BA.15
5 : CARBONATES (NITRATES)
B : Carbonates with additional anions, without H2O
A : With Cu, Co, Ni, Zn, Mg, Mn
5 : CARBONATES (NITRATES)
B : Carbonates with additional anions, without H2O
A : With Cu, Co, Ni, Zn, Mg, Mn
Dana 7th ed.:
16.4.2.1
16a.4.2.1
16a : ANHYDROUS CARBONATES CONTAINING HYDROXYL OR HALOGEN
4 : (AB)5(XO3)2Zq
16a : ANHYDROUS CARBONATES CONTAINING HYDROXYL OR HALOGEN
4 : (AB)5(XO3)2Zq
11.6.5
11 : Carbonates
6 : Carbonates of Zn and Cd
11 : Carbonates
6 : Carbonates of Zn and Cd
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 for Standard |
|---|---|---|
| Ach | 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 Aurichalcite
Pronunciation:
| Play | Recorded by | Country |
|---|---|---|
| Jolyon Ralph | United Kingdom |
Physical Properties of Aurichalcite
Silky, Pearly
Transparency:
Transparent
Colour:
Pale green, sky blue, or greenish blue; colourless to light shades of blue or green in transmitted light
Streak:
Light blue
Hardness:
1 - 2 on Mohs scale
Hardness Data:
Measured
Tenacity:
Fragile
Cleavage:
Perfect
Perfect on {010} and {100}.
Perfect on {010} and {100}.
Parting:
None
Fracture:
Irregular/Uneven
Density:
3.96 g/cm3 (Measured) 3.93 g/cm3 (Calculated)
Optical Data of Aurichalcite
Type:
Biaxial (-)
RI values:
nα = 1.655 nβ = 1.74 nγ = 1.744
2V:
Measured: 1° to 4°, Calculated: 22°
Max. Birefringence:
δ = 0.089
Based on recorded range of RI values above.
Based on recorded range of RI values above.
Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
Surface Relief:
Very High (positive)
Relative to Canada balsam mounting medium (n ≈ 1.537).
Relative to Canada balsam mounting medium (n ≈ 1.537).
This shows the grain boundary and Becke line effect under plane-polarised
light, based on the contrast between this mineral's average refractive
index and the mounting medium. It does not take into account mineral
colouration.
In focus
Interference Figure:
This shows the idealized biaxial acute bisectrix (Bxa) interference figure
- the conoscopic view for a grain cut perpendicular to the acute bisectrix, using
this mineral's 2V. The two small white dots mark the melatopes - the points
where the two optic axes emerge - and are shown only when they fall within the
field of view. The coloured bands are isochromatics, and the dark bands are
isogyres.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Dispersion:
relatively strong r < v
Pleochroism:
Weak
Comments:
X = Colourless
Y = Blue-green
Z = Blue-green
Y = Blue-green
Z = Blue-green
Chemistry of Aurichalcite
Mindat Formula:
(Zn,Cu)5(CO3)2(OH)6
Zn:Cu ratio is about 5:2, but may approach 2:1.
Zn:Cu ratio is about 5:2, but may approach 2:1.
Element Weights:
Common Impurities:
Ca
Crystallography of Aurichalcite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
P21/m
Cell Parameters:
a = 13.82 Å, b = 6.419 Å, c = 5.29 Å
β = 101.04°
β = 101.04°
Ratio:
a:b:c = 2.153 : 1 : 0.824
Unit Cell V:
460.59 ų (Calculated from Unit Cell)
Z:
2
Morphology:
Prismatic crystals elongated on [100], striated in {100} parallel to (001), (010), producing a fine grid-like appearance corresponding to cleavage planes or twinning directions. Delicate acicular or lath-like crystals; tufted, feathery, or plumose incrustations; columnar structure rare, granular.
Twinning:
Observed in X-ray studies.
Crystal Structure
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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) |
|---|---|---|---|---|---|---|---|
| 0009883 | Aurichalcite | Harding M M, Kariuki B M, Cernik R, Cressey G (1994) The structure of aurichalcite, (Cu,Zn)5(OH)6(CO3)2, determined from a microcrystal Acta Crystallographica B50 673-676 |  | 1994 | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Loading XRD data...
Data courtesy of RRUFF project at University of Arizona, used with permission.
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 6.78 Å | (100) |
| 3.68 Å | (70) |
| 3.25 Å | (30) |
| 2.89 Å | (40) |
| 2.81 Å | (30) |
| 2.72 Å | (40) |
| 2.61 Å | (80) |
| 1.656 Å | (40) |
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] |
Geological Setting:
A secondary mineral in oxidized copper and zinc ore deposits, typically as crusts.
Type Occurrence of Aurichalcite
Synonyms of Aurichalcite
Other Language Names for Aurichalcite
Basque:Aurikaltzita
Catalan:Auricalcita
Dutch:Aurichalciet
Japanese:水亜鉛銅鉱
Norwegian:Aurichalcitt
Russian:Аурихальцит
Simplified Chinese:绿铜锌矿
Slovak:Aurichalcit
Spanish:Auricalcita
Buratita
Buratita
Swedish:Aurikalcit
Ukrainian:Аурихальцит
Common Associates
Associations Based on Photo Data:
| 628 photos of Aurichalcite associated with Hemimorphite | Zn4Si2O7(OH)2 · H2O |
| 416 photos of Aurichalcite associated with Smithsonite | ZnCO3 |
| 403 photos of Aurichalcite associated with Calcite | CaCO3 |
| 215 photos of Aurichalcite associated with Rosasite | (Cu,Zn)2(CO3)(OH)2 |
| 186 photos of Aurichalcite associated with Malachite | Cu2(CO3)(OH)2 |
| 158 photos of Aurichalcite associated with Azurite | Cu3(CO3)2(OH)2 |
| 139 photos of Aurichalcite associated with Quartz | SiO2 |
| 86 photos of Aurichalcite associated with Hydrozincite | Zn5(CO3)2(OH)6 |
| 69 photos of Aurichalcite associated with Cerussite | PbCO3 |
| 67 photos of Aurichalcite associated with Goethite | Fe3+O(OH) |
Related Minerals - Strunz-mindat Grouping
| 5.BA.05 | Azurite | Cu3(CO3)2(OH)2 |
| 5.BA.10 | Mcguinnessite | (Mg,Cu)2(CO3)(OH)2 |
| 5.BA.10 | Zincrosasite | (Zn,Cu)2(CO3)(OH)2 |
| 5.BA.10 | Parádsasvárite | Zn2(CO3)(OH)2 |
| 5.BA.10 | Rosasite | (Cu,Zn)2(CO3)(OH)2 |
| 5.BA.10 | Nullaginite | Ni2(CO3)(OH)2 |
| 5.BA.10 | Georgeite | [Cu(OH)2-x(H2O)x][CO3]x/2 |
| 5.BA.10 | Glaukosphaerite | (Cu,Ni)2(CO3)(OH)2 |
| 5.BA.10 | Pokrovskite | Mg2(CO3)(OH)2 |
| 5.BA.10 | Kolwezite | CuCo(CO3)(OH)2 |
| 5.BA.10 | Chukanovite | Fe2+2(CO3)(OH)2 |
| 5.BA.10 | Malachite | Cu2(CO3)(OH)2 |
| 5.BA.10 | Perchiazziite | Co2(CO3)(OH)2 |
| 5.BA.15 | Hydrozincite | Zn5(CO3)2(OH)6 |
| 5.BA.20 | Holdawayite | Mn6(CO3)2(OH)7(Cl,OH) |
| 5.BA.25 | 'UM1977-03-COSiO:CaClH' | Ca10-11(CO3)7(SiO4)Cl1-2(OH)1-2 |
| 5.BA.25 | Defernite | Ca6(CO3)1.58(Si2O7)0.21(OH)7[Cl0.50(OH)0.08(H2O)0.42] |
| 5.BA.30 | Sclarite | Zn7(CO3)2(OH)10 |
| 5.BA.30 | Loseyite | (Mn2+,Zn,Mg)4Zn3(CO3)2(OH)10 |
Fluorescence of Aurichalcite
None
Other Information
Notes:
Soluble in acids and in ammonia.
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Industrial Uses:
A very minor ore of zinc and copper.
Internet Links for Aurichalcite
mindat.org URL:
https://www.mindat.org/min-422.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Aurichalcite
Reference List:
Glocker, Ernst Friedrich (1847) Generum et specierum mineralium, secundum ordines naturales digestorum synopsis, omnium, quotquot adhuc reperta sunt, mineralium nomina complectens [A synopsis of the genera and species of minerals, according to their natural orders, including the names of all the minerals that have yet been discovered.]. Eduardus Anton. 348 pp. p.230 - as Orichalcit
Collins, Henry F. (1892) Mineralogical Notes from Torreon, State of Chihuahua, Mexico. Mineralogical Magazine and Journal of the Mineralogical Society, 10 (45) 15-19 doi:10.1180/minmag.1892.010.45.04
Heddle, M. Forster; Goodchild, J.G. - Ed. (1901) The Mineralogy of Scotland Vol. 1. David Douglas. p.146
Larsen, Esper S. (1921) The microscopic determination of the nonopaque minerals. Bulletin 679. US Geological Survey doi:10.3133/b679 p.43
Jambor, J. L., Pouliot, G. (1965) X-ray crystallography of aurichalcite and hydrozincite. The Canadian Mineralogist, 8 (3) 385-389
Alwan, Alwan K., Thomas, J. H., Williams, Peter A. (1980) Mineral formation from aqueous solution. Part III. The stability of aurichalcite, (Zn,Cu)5(CO3)2(OH)6, and rosasite (Cu,Zn)2(CO3)(OH)2. Transition Metal Chemistry, 5 (1). 3-5 doi:10.1007/bf01396855
Harding, M. M., Kariuki, B. M., Cernik, R., Cressey, G. (1994) The structure of aurichalcite, (Cu,Zn)5(OH)6(CO3)2, determined from a microcrystal. Acta Crystallographica Section B Structural Science, 50 (6) 673-676 doi:10.1107/s0108768194007470
Reddy, B. J. (2004) Spectroscopic characterisation of rosasite and aurichalcite. Neues Jahrbuch für Mineralogie - Monatshefte, 2004 (7) 302-316 doi:10.1127/0028-3649/2004/2004-0302
Frost, Ray L., Hales, Matt C., Jagannadha Reddy, B. (2007) Aurichalcite – An SEM and Raman spectroscopic study. Polyhedron, 26 (13). 3291-3300 doi:10.1016/j.poly.2007.03.003
Frost, Ray L., Locke, Ashley, Reddy, B. Jagannadha, Hales, Matt C. (2008) Synthesis and vibrational spectroscopic characterisation of nickel containing aurichalcite. Polyhedron, 27 (3) 1033-1040 doi:10.1016/j.poly.2007.11.032
Frost, R. L., Locke, A. J., Hales, M. C., Martens, W. N. (2008) Thermal stability of synthetic aurichalcite implications for making mixed metal oxides for use as catalysts. Journal of Thermal Analysis and Calorimetry, 94 (1) 203-208 doi:10.1007/s10973-007-8634-2
Localities for Aurichalcite
Showing 1,157 localities.
symbol to view information about a locality.
The Locality List
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- This locality has estimated coordinates.
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- 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.
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Blue Bell Mine, Zzyzx, Soda Mountains, Silver Lake Mining District, San Bernardino County, California, USA