Monazite-(Gd)

Gd(PO4)
IMA status
  • Approved
IMA symbol
Mnz-Gd
IMA approved
2022
Also known as
  • IMA2022-055
  • Monaziet-(Gd)

Where it forms, where it's found

Geological setting

quartz-muscovite vein within phyllites, in a granite exocontact

Type locality
Zimná Voda uranium occurrence
  1. Prakovce
  2. Gelnica District
  3. Košice Region
  4. Slovakia

48.7667°, 20.9134°

2recorded occurrences
Source · OpenStreetMap

Physical

Density
5.55 g/cm³

Crystallography

Crystal system
Monoclinic
Cell parameters
a = 6.703(1) Å · b = 6.914(1) Å · c = 6.383(1) Å
Cell angles
β = 103.8(1) °
Ratio a:b:c
1 : 1.031 : 0.952
Z
4
Type-locality form

anhedral domains, ≤100 (usually 10–50 ) μm in diameter

Comment

Spacegroup is P21/n

Crystal structure

Chemical composition

Constituent elements
Mass composition breakdown
ElementAtoms At. mass g/mol Mass g/molMass share
64GdGadoliniumGadolinium1157.250157.250
62.35%
8OOxygenOxygen415.99963.996
25.37%
15PPhosphorusPhosphorus130.97430.974
12.28%
Total252.220100.00%

Mass share = atoms × atomic mass ÷ molar mass × 100

From IMA formula

Synonyms

  • IMA2022-055
  • Monaziet-(Gd)

In other languages

German
IMA 2022-055 · Monazit-(Gd)

Classification

Strunz
10th ed.

8.AD

  • 8Phosphates, Arsenates, VanadatesClass
  • 8.APhosphates, etc. without additional anions, without H2ODivision
  • 8.ADWith only large cationsGroup
  • 8.ADMonazite-(Gd)Species

Group, growth & confusion

In the same group
4 members
Commonly confused with
1 mineral

Literature, links & citation

Citations
  1. 1985Mullica, D.F.; Grossie, David A.; Boatner, L.A. (1985) Coordination geometry and structural determinations of SmPO4, EuPO4 and GdPO4. Inorganica Chimica Acta, 109 (2). p.105-110. doi:10.1016/s0020-1693(00)84549-1DOI: 10.1016/s0020-1693(00)84549-1
  2. 2018Gysi, Alexander P., Harlov, Daniel, Miron, George D. (2018) The solubility of monazite (CePO4), SmPO4, and GdPO4 in aqueous solutions from 100 to 250 °C. Geochimica et Cosmochimica Acta, 242. 143-164 doi:10.1016/j.gca.2018.08.038DOI: 10.1016/j.gca.2018.08.038
  3. 2022Miyawaki, Ritsuro, Hatert, Frédéric, Pasero, Marco, Mills, Stuart J. (2022) IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) – Newsletter 70. European Journal of Mineralogy, 34 (6) 591-601 doi:10.5194/ejm-34-591-2022 DOI: 10.5194/ejm-34-591-2022
  4. 2023Ondrejka, Martin, Uher, Pavel, Ferenc, Štefan, Milovská, Stanislava, Mikuš, Tomáš, Molnárová, Alexandra, Škoda, Radek, Kopáčik, Richard, Bačík, Peter (2023) Gadolinium-dominant monazite and xenotime: Selective hydrothermal enrichment of middle REE during low-temperature alteration of uraninite, brannerite, and fluorapatite (the Zimná Voda REE-U-Au quartz vein, Western Carpathians, Slovakia) American Mineralogist, 108 (4) Mineralogical Society of America. 754-768 doi:10.2138/am-2022-8418DOI: 10.2138/am-2022-8418
  5. 2023Ondrejka, Martin, Uher, Pavel, Ferenc, Štefan, Majzlan, Juraj, Pollok, Kilian, Mikuš, Tomáš, Milovská, Stanislava, Molnárová, Alexandra, Škoda, Radek, Kopáčik, Richard, Kurylo, Sergii, Bačík, Peter (2023) Monazite-(Gd), a new Gd-dominant mineral of the monazite group from the Zimná Voda REE–U–Au quartz vein, Prakovce, Western Carpathians, Slovakia. Mineralogical Magazine, 87 (4) 568-574 doi:10.1180/mgm.2023.37DOI: 10.1180/mgm.2023.37
Cite this entry
@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Monazite-(Gd) — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/monazite-gd-470481},
  note      = {Accessed 2026-05-11}
}