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Palladodymite
A valid IMA mineral species
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About Palladodymite
Formula:
(Pd,Rh)2As
Lustre:
Metallic
Specific Gravity:
11.3 (Calculated)
Crystal System:
Orthorhombic
Name:
From (pallad)ium and the Greek for twin as it is the palladium-dominant analogue of rhodarsenide.
Type Locality:
This page provides mineralogical data about Palladodymite.
Unique Identifiers
Mindat ID:
7214
Long-form identifier:
mindat:1:1:7214:0
IMA Classification of Palladodymite
Approved
IMA Formula:
Pd2As
Approval year:
1997
First published:
1999
Classification of Palladodymite
2.AC.25c
2 : SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulfantimonites, sulfbismuthites, etc.)
A : Alloys
C : Alloys of metalloids with PGE
2 : SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulfantimonites, sulfbismuthites, etc.)
A : Alloys
C : Alloys of metalloids with PGE
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 |
|---|---|---|
| Pdd | 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 Palladodymite
Metallic
Transparency:
Opaque
Hardness:
VHN20=546 - 611 kg/mm2 - Vickers
Tenacity:
Brittle
Cleavage:
None Observed
Density:
11.3 g/cm3 (Calculated)
Optical Data of Palladodymite
Anisotropism:
Distinctly anisotropic from bluish gray to reddish brown.
Reflectivity:
| Wavelength | R1 (%) | R2 (%) |
|---|---|---|
| 420nm | 50.5% | 45.5% |
| 440nm | 50.6% | 45.4% |
| 460nm | 50.7% | 45.5% |
| 480nm | 51.6% | 45.8% |
| 500nm | 52.6% | 46.5% |
| 520nm | 53.3% | 46.9% |
| 540nm | 54.0% | 46.8% |
| 560nm | 54.8% | 46.9% |
| 580nm | 56.2% | 48.0% |
| 600nm | 57.6% | 48.5% |
| 620nm | 57.8% | 48.9% |
| 640nm | 58.2% | 49.5% |
| 660nm | 59.1% | 50.2% |
| 680nm | 59.7% | 50.6% |
| 700nm | 60.6% | 50.8% |
Graph shows reflectance levels at different wavelengths (in nm). Peak reflectance is 60.6%.
R1 shown in black, R2 shown in red
Colour in reflected light:
Brownish gray with a bluish tint.
Chemistry of Palladodymite
Mindat Formula:
(Pd,Rh)2As
Elements listed:
Crystallography of Palladodymite
Crystal System:
Orthorhombic
Class (H-M):
mmm(2/m2/m2/m) - Dipyramidal
Space Group:
Pnma
Cell Parameters:
a = 5.91(2) Å, b = 3.90(1) Å, c = 7.34(2) Å
Ratio:
a:b:c = 1.515 : 1 : 1.882
Unit Cell V:
169.18 ų (Calculated from Unit Cell)
Z:
4
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 2.43 Å | (100) |
| 2.24 Å | (50) |
| 1.838 Å | (30) |
| 2.06 Å | (10) |
| 1.710 Å | (10) |
| 1.484 Å | (10) |
| 1.380 Å | (10) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Near-surface Processes | |
| 26 : Hadean detrital minerals | |
| High-? alteration and/or metamorphism | |
| 33 : Minerals deposited by hydrothermal metal-rich fluids (see also [#12]) | |
| Stage 4b: Highly evolved igneous rocks | >3.0 |
| 37 : Layered igneous intrusions and related PGE minerals |
Type Occurrence of Palladodymite
General Appearance of Type Material:
Inclusions, up to 30 × 70 µm, in native ruthenium.
Place of Conservation of Type Material:
Mining Museum, Saint Petersburg Mining Institute, Russia.
Geological Setting of Type Material:
Placer deposit
Associated Minerals at Type Locality:
Synonyms of Palladodymite
Other Language Names for Palladodymite
Common Associates
Associations Based on Photo Data:
| 1 photo of Palladodymite associated with Hongshiite | PtCu |
| 1 photo of Palladodymite associated with Native Ruthenium | (Ru,Ir) |
| 1 photo of Palladodymite associated with Vincentite | Pd3As |
| 1 photo of Palladodymite associated with Cherepanovite | RhAs |
| 1 photo of Palladodymite associated with Isoferroplatinum | Pt3Fe |
Related Minerals - Strunz-mindat Grouping
| 2.AC. | Vadlazarenkovite | Pd8Bi1.5Te1.25As0.25 |
| 2.AC. | Törnroosite | Pd11As2Te2 |
| 2.AC.05b | Vincentite | Pd3As |
| 2.AC.05a | Atheneite | Pd2As0.75Hg0.25 |
| 2.AC.10c | Arsenopalladinite | Pd8(As,Sb)3 |
| 2.AC.10b | Mertieite | Pd8Sb2.5As0.5 |
| 2.AC.10a | Stillwaterite | Pd8As3 |
| 2.AC.15a | Isomertieite | Pd11Sb2As2 |
| 2.AC.15a | Miessiite | Pd11Te2Se2 |
| 2.AC.15b | Pseudomertieite | Pd11(Sb,As)4 |
| 2.AC.20c | Menshikovite | Pd3Ni2As3 |
| 2.AC.20a | Stibiopalladinite | Pd5Sb2 |
| 2.AC.20b | Palarstanide | Pd5(Sn,As)2 |
| 2.AC.25d | Naldrettite | Pd2Sb |
| 2.AC.25b | Rhodarsenide | (Rh,Pd)2As |
| 2.AC.25e | Majakite | PdNiAs |
| 2.AC.25a | Palladoarsenide | Pd2As |
| 2.AC.25f | Palladobismutharsenide | Pd2(As,Bi) |
| 2.AC.30 | 'UM1999-02-As:NiRh' | (Rh,Ni)7As4 |
| 2.AC.30 | Polkanovite | Rh12As7 |
| 2.AC.35b | Ungavaite | Pd4Sb3 |
| 2.AC.35a | Genkinite | Pt4Sb3 |
| 2.AC.40 | Polarite | Pd(Bi,Pb) |
| 2.AC.45a | Froodite | α-PdBi2 |
| 2.AC.50 | Viteite | Pd5InAs |
| 2.AC.50 | Nipalarsite | Ni8Pd3As4 |
Miass River, Chelyabinsk Oblast, Russia