Praseodymium (Pr)

We are a leading manufacturer and supplier of research materials

Praseodymium 59Pr140.907

Separated in 1885 by Baron Auer von Welsbach at Vienna, Austria.

[Greek, prasios didymos = green twin]

French: praséodyme
German: Praseodym
Italian: praseodimio
Spanish: praseodimio

Description: Preseodymium is a soft, malleable, silvery metal of the so-called rare earth group (more correctly termed the lanthanides). It reacts slowly with oxygen and rapidly with water. Praeseodymium is used in alloys for permanent magnets and flints. It is used to make the yellow glass for eye protection for welders, etc.


Further Materials properties


Crystal structure:

(cell dimensions/pm), space group, 
α-Pr h.c.p. (a=367.25, c=1183.5), P63/mmc
β-Pr b.c.c. (a=413), Im3m

X-ray diffractions mass absorption coefficients: CuKa 363 (µ/r) / cm2g-1
MoKa 50.7 (µ/r) / cm2g-1
Neutron scattering length: 0.445 b/10-12 cm
Thermal neutron capture cross-section: 11.5 sa / barns
Density: 6773 kg/m-3 [293 K]
Melting point: 930.85°C / 1204°K
Boiling point: 3511.85°C / 3785°K
Molar volume: 20.80 cm3
Thermal conductivity: 12.5 [300 K] W m-1K-1
Coefficient of linear thermal expansion: 6.79 x 10-6 K-1
Electrical resistivity: 68 x 10-8 [298 K] Ωm
Mass magnetic susceptibility: +4.47 x 10-7(s) kg-1m3
Radi: Pr4+ 92; Pr3+ 106; atomic 183; covalent 165
Electronegativity: 1.13 (Pauling); 1.07 (Allred); ≤ 3.0 eV (absolute)
Effective nuclear charge: 2.85 (Slater); 7.75 (Clementi); 10.70 (Froese-Fischer)
Number of Isotopes (incl. nuclear isomers): 26
Isotope mass range: 132 -> 152



Biological data


Biological role: None, but acts to stimulate metabolism.
Toxic intake: n.a.
Lethal intake: LD50 (chloride, oral, rat) = 4200 mg kg-1
Hazards: Praeseodymium is mildly toxic by ingestion, and is a skin and eye irritant.
Level in humans n.a. but very low
Daily dietary intake: n.a. 
Total mass of element in average
[70 kg] person:
n.a. but very low


Geological data

MineralFormulaDensityHardnessCrystal apperance
Bastnäsite*  (La,Ce,etc.)CO3F 4.9  4 - 5.5  hex., vit./greasy yellow
Monazite*  (Ce, La, Nd, Th, etc.)PO4 5.20  5 - 5.5  mon., waxy/vit. yellow-brown

* Although not a major constituent, praseodymium is present in extractable amounts.

Chief ores: monazite, bastnäsite
World production: 2400 tonnes/year
Producing areas: USA, Brazil, India, Sri Lanka, Australia
Reserves: c. 2 x 106 tonnes
Specimen: available as chips, foil and ingots. Safe. Pr powder is a skin and eye irritant. Care!


Sun: 4.6 (relative to H = 1 x 1012)
Earth's crust: 9.5 ppm
Atlantic surface: 4 x 10-7 ppm
Atlantic deep: 7 x 10-7 ppm
Pacific surface: 4.4 x 10-7 ppm
Pacific deep: 10 x 10-7 ppm
Residence time: n.a.
Oxidation state: III

  Source: Emsley, J. (1998) The Elements (3rd Edition)

Other sizes and specifications on request

Overview of elements with access to our shop

1 18
2 13 14 15 16 17
Li Be B C
Na Mg 3 4 5 6 7 8 9 10 11 12 Al Si P S
K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se
Rb Sr Y Zr Nb Mo
Ru Rh Pd Ag Cd In Sn Sb Te I
Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi
Ce Pr Nd
Sm Eu Gd Tb Dy Ho Er Tm Yb Lu

Get our latest news and special sales
You may unsubscribe at any moment. For that purpose, please find our contact info in the legal notice.
Tel.: +49 (0) 2461 - 9352 - 0
Fax: +49 (0) 2461 - 9352 - 11