Agardite-(Nd)
A valid IMA mineral species
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About Agardite-(Nd)
Formula:
NdCu6(AsO4)3(OH)6 · 3H2O
Colour:
Grass-green, greenish, greenish-blue
Lustre:
Vitreous, Silky
Hardness:
3 - 4
Crystal System:
Hexagonal
Member of:
Originally an incompletely characterised member of the Mixite Group, published without approval.
Finally approved in 2010, based on material from the Hilarion Mine, Lavrion, Greece.
Quantitative analyses are generally needed to ensure that the Mixite-group sample in question is really Nd-dominant, and not simply a Nd-rich variety.
Originally reported from Wittichen, Schenkenzell, Black Forest, Baden-Württemberg, Germany.
Finally approved in 2010, based on material from the Hilarion Mine, Lavrion, Greece.
Quantitative analyses are generally needed to ensure that the Mixite-group sample in question is really Nd-dominant, and not simply a Nd-rich variety.
Originally reported from Wittichen, Schenkenzell, Black Forest, Baden-Württemberg, Germany.
Unique Identifiers
IMA Classification of Agardite-(Nd)
Classification of Agardite-(Nd)
8.DL.15
8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
L : With large and medium-sized cations, (OH, etc.):RO4 = 2:1
8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
L : With large and medium-sized cations, (OH, etc.):RO4 = 2:1
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 |
---|---|---|
Agr-Nd | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Physical Properties of Agardite-(Nd)
Vitreous, Silky
Transparency:
Transparent
Comment:
Vitreous in crystals and silky in aggregates.
Colour:
Grass-green, greenish, greenish-blue
Streak:
White, greenish white
Hardness:
3 - 4 on Mohs scale
Tenacity:
Brittle
Cleavage:
None Observed
Fracture:
Irregular/Uneven
Comment:
Density could not be measured.
Optical Data of Agardite-(Nd)
Type:
Uniaxial (+)
RI values:
nω = 1.709 - 1.712 nε = 1.775 - 1.780
Max Birefringence:
δ = 0.066

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:
High
Pleochroism:
Strong
Comments:
O = pale turquoise; E = bright green-blue.
Comments:
Absorption: E > O.
Chemistry of Agardite-(Nd)
Mindat Formula:
NdCu6(AsO4)3(OH)6 · 3H2O
Crystallography of Agardite-(Nd)
Crystal System:
Hexagonal
Class (H-M):
6/m - Dipyramidal
Space Group:
P63/m
Cell Parameters:
a = 13.548(8) Å, c = 5.894(6) Å
Ratio:
a:c = 1 : 0.435
Unit Cell V:
936.90 ų (Calculated from Unit Cell)
X-Ray Powder Diffraction
Powder Diffraction Data:
d-spacing | Intensity |
---|---|
11.70 Å | (100) |
4.443 Å | (22) |
3.545 Å | (18) |
3.255 Å | (8) |
2.935 Å | (18) |
2.695 Å | (13) |
2.559 Å | (10) |
2.453 Å | (30) |
Comments:
Hilarion Mine, Kamariza Mines, Attica, Greece. The data are from Pekov et al. (2011).
Geological Environment
Paragenetic Mode(s):
Paragenetic Mode | Earliest Age (Ga) |
---|---|
Stage 7: Great Oxidation Event | <2.4 |
47a : [Near-surface hydration of prior minerals] | |
47d : [Arsenates, antimonates, selenates, bismuthinates] |
Type Occurrence of Agardite-(Nd)
General Appearance of Type Material:
Thin, acicular to hair-like crystals up to 0.5 mm long and up to 5 μm thick, elongate along [001], with a hexagonal cross section. Also occurs with agardite-(Y) and/or agardite-(La) to form rims, up to 3 μm thick, in zoned acicular crystals, up to 0.015 × 1.2 mm, with a core of zálesíite. Typically in sprays or radiating clusters up to 2 mm.
Place of Conservation of Type Material:
Fersman Mineralogical Museum of Russian Academy of Sciences, Moscow, Russia, number 4020/1.
Geological Setting of Type Material:
In cavities of an oxidized ore (primarily goethite) and in cracks of supergene altered mica schist.
Associated Minerals at Type Locality:
Synonyms of Agardite-(Nd)
Other Language Names for Agardite-(Nd)
Relationship of Agardite-(Nd) to other Species
Member of:
Other Members of this group:
Agardite-(Ce) | CeCu6(AsO4)3(OH)6 · 3H2O | Hex. 6/m : P63/m |
Agardite-(La) | LaCu6(AsO4)3(OH)6 · 3H2O | Hex. 6/m : P63/m |
Agardite-(Y) | YCu6(AsO4)3(OH)6 · 3H2O | Hex. 6/m : P63/m |
Calciopetersite | CaCu6(PO4)2(PO3OH)(OH)6 · 3H2O | Hex. 6/m : P63/m |
Goudeyite | AlCu6(AsO4)3(OH)6 · 3H2O | Hex. |
Mixite | BiCu6(AsO4)3(OH)6 · 3H2O | Hex. 6/m : P63/m |
Petersite-(Ce) | Cu6Ce(PO4)3(OH)6 · 3H2O | Hex. 6/m : P63/m |
Petersite-(La) | Cu6La(PO4)3(OH)6 · 3H2O | Hex. 6/m : P63/m |
Petersite-(Y) | (Y,Ce,Nd)Cu6(PO4)3(OH)6 · 3H2O | Hex. |
Plumboagardite | (Pb,REE,Ca)Cu6(AsO4)3(OH)6 · 3H2O | Hex. 6/m : P63/m |
Zálesíite | CaCu6(AsO4)2(AsO3OH)(OH)6 · 3H2O | Hex. 6/m : P63/m |
Common Associates
Associated Minerals Based on Photo Data:
16 photos of Agardite-(Nd) associated with Conichalcite | CaCu(AsO4)(OH) |
3 photos of Agardite-(Nd) associated with Adamite | Zn2(AsO4)(OH) |
2 photos of Agardite-(Nd) associated with Brochantite | Cu4(SO4)(OH)6 |
2 photos of Agardite-(Nd) associated with Malachite | Cu2(CO3)(OH)2 |
1 photo of Agardite-(Nd) associated with Pseudomalachite | Cu5(PO4)2(OH)4 |
1 photo of Agardite-(Nd) associated with Chalcedony | SiO2 |
1 photo of Agardite-(Nd) associated with Agardite-(La) | LaCu6(AsO4)3(OH)6 · 3H2O |
1 photo of Agardite-(Nd) associated with Libethenite | Cu2(PO4)(OH) |
Related Minerals - Strunz-mindat Grouping
8.DL.05 | Foggite | CaAl(PO4)(OH)2 · H2O |
8.DL.10 | Fluorowardite | NaAl3(PO4)2F2(OH)2(H2O)2 |
8.DL.10 | Wardite | NaAl3(PO4)2(OH)4 · 2H2O |
8.DL.10 | Millisite | (Na,K)CaAl6(PO4)4(OH)9 · 3H2O |
8.DL.10 | Cyrilovite | NaFe3+3(PO4)2(OH)4 · 2H2O |
8.DL.15 | Petersite-(Ce) | Cu6Ce(PO4)3(OH)6 · 3H2O |
8.DL.15 | Agardite-(Y) | YCu6(AsO4)3(OH)6 · 3H2O |
8.DL.15 | Agardite-(Ce) | CeCu6(AsO4)3(OH)6 · 3H2O |
8.DL.15 | Agardite-(Dy) | (Dy,La)Cu6(AsO4)3(OH)6 · 3H2O |
8.DL.15 | Agardite-(La) | LaCu6(AsO4)3(OH)6 · 3H2O |
8.DL.15 | Petersite-(Y) | (Y,Ce,Nd)Cu6(PO4)3(OH)6 · 3H2O |
8.DL.15 | Zálesíite | CaCu6(AsO4)2(AsO3OH)(OH)6 · 3H2O |
8.DL.15 | Mixite | BiCu6(AsO4)3(OH)6 · 3H2O |
8.DL.15 | Petersite-(La) | Cu6La(PO4)3(OH)6 · 3H2O |
8.DL.15 | Goudeyite | AlCu6(AsO4)3(OH)6 · 3H2O |
8.DL.15 | Calciopetersite | CaCu6(PO4)2(PO3OH)(OH)6 · 3H2O |
8.DL.15 | Plumboagardite | (Pb,REE,Ca)Cu6(AsO4)3(OH)6 · 3H2O |
8.DL.20 | Dugganite | Pb3Zn3(AsO4)2(TeO6) |
8.DL.20 | Wallkilldellite | Ca2Mn2+3(AsO4)2(OH)4 · 9H2O |
8.DL.20 | Wallkilldellite-(Fe) | (Ca,Cu)4Fe2+6(AsO4,SiO4)4(OH,O)8 · 18H2O |
8.DL.20 | Cheremnykhite | Pb3Zn3(VO4)2(TeO6) |
8.DL.20 | Kuksite | Pb3Zn3(PO4)2(TeO6) |
8.DL.25 | Angastonite | CaMgAl2(PO4)2(OH)4 · 7H2O |
8.DL.30 | Långbanshyttanite | Pb2Mn2Mg(AsO4)2(OH)4 · 6H2O |
Fluorescence of Agardite-(Nd)
Not fluorescent.
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 Agardite-(Nd)
mindat.org URL:
https://www.mindat.org/min-43.html
Please feel free to link to this page.
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Search Engines:
External Links:
References for Agardite-(Nd)
Reference List:
Williams, P. A., Hatert, F., Pasero, M., Mills, S. J. (2011) New minerals and nomenclature modifications approved in 2010, CNMNC Newsletter No 7. Mineralogical Magazine, 75 (1) 27-31 doi:10.1180/minmag.2011.075.1.27
Pekov, I. V., Chukanov, N. V., Zadov, A. E., Voudouris, P., Magganas, A., Katerinopoulos, A. (2011) Agardite-(Nd) NdCu6(AsO4)3(OH)6·3H2O from the Hilarion Mine, Lavrion, Greece: mineral description and chemical relations with other members of the agardite-zálesíite solid-solution system. Journal of GEOsciences, 56 (3) 249-255
Localities for Agardite-(Nd)
Locality List




All localities listed without proper references should be considered as questionable.
Australia | |
| Leverett et al. (2003) |
| Downes et al. (2006) |
Austria | |
| Kolitsch (2014) |
| Exel (1993) +1 other reference |
Bulgaria | |
| Kunov +2 other references |
France | |
| |
Germany | |
| [Wittern (1995) +1 other reference |
| Göb et al. (2011) |
| Walenta et al. (2004) |
Walenta (1992) | |
Walenta (1992) | |
| Walenta (1992) |
| Walenta (1992) |
| Walenta (1992) +1 other reference |
Greece (TL) | |
| Williams et al. (2011) +1 other reference |
Italy | |
| Collected by F. Castellaro and probed ... |
| Guastoni et al. (2017) |
| Guastoni et al. (2017) |
Guastoni et al. (2017) | |
UK | |
| Embrey (1978) +1 other reference |
USA | |
| Castor et al. (2004) |
Dakota Matrix - Tom Loomis | |
| Castor et al. (2004) |
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Hilarion Mine, Kamariza Mines, Agios Konstantinos, Lavrion Mining District, Lavreotiki, East Attica, Attica, Greece