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About Gagarinite-(Y)Hide

Yurii Alexeevich Gagarin - the first man visited space.
Creamy, yellowish, pink.
Vitreous, Dull
Specific Gravity:
4.11 - 4.29
Crystal System:
Originally named simply gagarinite in honor of Yuri Alexeevich Gagarin (9 March 1934, Klushino, Smolensk Oblast, Soviet Union - 27 March 1968, Novosyolovo, Soviet Union), cosmonaut and the first person in space. The suffix was added by the IMA in 1987 to denote the dominant rare earth element.
Y-analogue of gagarinite-(Ce) and CaY-analogue of polezhaevaite-(Ce).

Possibly isostructural with (or identical to?) UM1993-06-F:CaNaREEY.

Classification of Gagarinite-(Y)Hide

First Published:

A : Simple halides, without H2O
B : M:X = 1:2

5 : AmBX6

8 : Halides - Fluorides, Chlorides, Bromides and Iodides; also Fluoborates and Fluosilicates
7 : Halides of the rare earth metals

Physical Properties of Gagarinite-(Y)Hide

Vitreous, Dull
Transparent, Translucent
Creamy, yellowish, pink.
4½ on Mohs scale
VHN100=367 - 372 - Vickers
Distinct in one direction, prismatic
4.11 - 4.29 g/cm3 (Measured)    4.27 g/cm3 (Calculated)

Optical Data of Gagarinite-(Y)Hide

Uniaxial (+)
RI values:
nω = 1.472 - 1.475 nε = 1.490 - 1.493
Measured: 20°
Max Birefringence:
δ = 0.018
Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
Surface Relief:
May be anomalously biaxial

Chemical Properties of Gagarinite-(Y)Hide


Crystallography of Gagarinite-(Y)Hide

Crystal System:
Class (H-M):
6/m - Dipyramidal
Space Group:
Cell Parameters:
a = 5.987(2) Å, c = 3.5413(7) Å
a:c = 1 : 0.591
Unit Cell V:
109.93 ų (Calculated from Unit Cell)
Short and long prismatic hexagonal crystals, irregular grains, aggregates

Type Occurrence of Gagarinite-(Y)Hide

Synonyms of Gagarinite-(Y)Hide

Other Language Names for Gagarinite-(Y)Hide

Common AssociatesHide

Associated Minerals Based on Photo Data:
6 photos of Gagarinite-(Y) associated with ThomsenoliteNaCa[AlF6] · H2O
5 photos of Gagarinite-(Y) associated with CryoliteNa2NaAlF6
4 photos of Gagarinite-(Y) associated with QuartzSiO2
4 photos of Gagarinite-(Y) associated with AnniteKFe2+3(AlSi3O10)(OH)2
2 photos of Gagarinite-(Y) associated with Riebeckite◻[Na2][Fe2+3Fe3+2]Si8O22(OH)2
1 photo of Gagarinite-(Y) associated with Monazite-(Ce)Ce(PO4)
1 photo of Gagarinite-(Y) associated with AegirineNaFe3+Si2O6
1 photo of Gagarinite-(Y) associated with Bastnäsite-(Y)Y(CO3)F

Related Minerals - Nickel-Strunz GroupingHide

3.AB.FluorocronitePbF2Iso. m3m (4/m 3 2/m) : Fm3m
3.AB.15SellaiteMgF2Tet. 4/mmm (4/m 2/m 2/m) : P42/mnm
3.AB.20Lawrencite(Fe2+,Ni)Cl2Trig. 3m (3 2/m) : R3m
3.AB.20ScacchiteMnCl2Trig. 3m (3 2/m) : R3m
3.AB.25FluoriteCaF2Iso. m3m (4/m 3 2/m) : Fm3m
3.AB.25FrankdicksoniteBaF2Iso. m3m (4/m 3 2/m) : Fm3m
3.AB.25StrontiofluoriteSrF2Iso. m3m (4/m 3 2/m) : Fm3m
3.AB.30Tveitite-(Y)(Y, Na)6Ca6Ca6F42Trig. 3 : R3
3.AB.35Polezhaevaite-(Ce)NaSrCeF6Hex. 6/m : P63/m

Related Minerals - Dana Grouping (8th Ed.)Hide 6/m : P63/m

Related Minerals - Hey's Chemical Index of Minerals GroupingHide

8.7.1Fluocerite-(Ce)(Ce,La)F3Trig. 3m (3 2/m) : P3c1
8.7.2Fluocerite-(La)(La,Ce)F3Trig. 3m (3 2/m) : P3c1
8.7.3Tveitite-(Y)(Y, Na)6Ca6Ca6F42Trig. 3 : R3

Fluorescence of Gagarinite-(Y)Hide

Not fluorescent

Other InformationHide

Thermal Behaviour:
Large endothermal break at 720-750 and a small exothermal break at about 900. When heated the mineral loses water and part of the fluorine above 500.
Weakly magnetic
Special Storage/
Display Requirements:
Decomposed by water. Easily decomposed by HNO3, HCl, and concentrated H2SO4.
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

References for Gagarinite-(Y)Hide

Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
Stepanov, A.V., Severov, E.A. (1961) Gagarinite, a new rare-earth mineral. Doklady Akademii Nauk SSSR: 141: 954-957.
Fleischer, M. (1962) New mineral names. American Mineralogist: 47: 805-812.
International Mineralogical Association (1967) Commission on new minerals and mineral names. Mineralogical Magazine: 36: 131-136.
Doklady of the Academy of Sciences of the USSR, Earth Science Sections: 141: 1290-1293.
Nickel, E.H., Mandarino, J.A. (1987) Procedures involving the IMA Commission on New Minerals and Mineral Names and guidelines on mineral nomenclature. American Mineralogist: 72: 1031-1042.
Frank-Kamenetskaya, O.V., Fundamenskii, V.S., Tsytsenko, A.K., Frank-Kamenetskii, V.A. (1994) Crystal structure of gagarinite from precision X-ray data: Structural changes in the NaCaTRF6-Na1.5TR1.5F6 series. Crystallography Reports: 39: 923-928.
Hughes, J.M., Drexler, J.W. (1994) Refinement of the structure of gagarinite-(Y), Nax(CaxREE2-x)F6. The Canadian Mineralogist: 32: 563-565.
Jambor, J.L., Roberts, A.C., Owens, D.R., Grice, J.D. (1996) Zajacite-(Ce), a new rare-earth fluoride from the Strange Lake deposit, Quebec-Labrador. The Canadian Mineralogist: 34: 1299-1304.
Jambor, J.L., Pertsev, N.N., Roberts, A.C. (1997) New mineral names. American Mineralogist: 82: 1038-1041.
Williams, P.A., Hatert, F., Pasero, M., Mills, S.J. (2010) IMA Commission on new minerals, nomenclature and classification (CNMNC) Newsletter 6. New minerals and nomenclature modifications approved in 2010. Mineralogical Magazine: 74: 941-942.
Sciberras, M.J., Leverett, P., Williams, P.A., Hibbs, D.E., Roberts, A.C., Grice, J.D. (2011) The single-crystal X-ray structure of gagarinite-(Ce). The Canadian Mineralogist: 49: 1111-1114.

Internet Links for Gagarinite-(Y)Hide

Localities for Gagarinite-(Y)Hide

This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.

Locality ListHide

- This locality has map coordinates listed. - This locality has estimated coordinates. ⓘ - Click for further information on this occurrence. ? - Indicates mineral may be doubtful at this locality. - 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). Struck out - Mineral was erroneously reported from this locality. Faded * - Never found at this locality but inferred to have existed at some point in the past (eg from pseudomorphs.)

All localities listed without proper references should be considered as questionable.
  • Amazonas
    • Presidente Figueiredo
      • Pitinga mine
A. C. Bastos Neto, V. P. Pereira, L. H. Ronchi, E. F. de Lima and J. C. Frantz (2009): The world-class Sn, Nb, Ta, F (Y, REE, Li) deposit and the massive cryolite associated with the albite-enriched facies of the Madeira A-type granite, Pitinga mining district, Amazonas State, Brazil. Canadian Mineralogist 47, 1329-1357.
Miller (1996), Canadian Mineralogist: 34:349-371; Salvi & Williams-Jones (1995); Am.Min.: 80:1031-1040; Miller (1990), Newfoundland Dept. of Mines & Energy Geol. Sur. Report 90-1: 171-182.; A. Kerr and H. Rafuse (2012) Rare-earth element (REE) geochemistry of the Strange Lake deposits: Implications for resource estimation and metallogenic models. Newfoundland and Labrador Department of Natural Resources Current Research 2012 pp39-60; BIRKETT, T.C., MILLER, R.R., ROBERTS, A.C., & MARIANO, A.N. (1992) Zirconium bearing minerals from the Strange Lake intrusive complex, Quebec Labrador. Canadian Mineralogist, 30, 191-205.; BROSSEAU-LIARD, A. (2012) The nature and origin of REE and associated rare metal mineralization in the B-Zone at Strange Lake, Québec. Unpublished M.Sc. Thesis, McGill University, Montréal, Québec. 154 p.
Kazakhstan (TL)
  • East Kazakhstan
    • Tarbagatai Range
      • Akzhaylyautas Mts (Akzhailyautas Mts; Akjaylautas Mts; Akzhalautas Mts)
DAN-SSSR,(1961) 141, 954-957; Pekov, I. (1998) Minerals First discovered on the territory of the former Soviet Union 369p. Ocean Pictures, Moscow; Bailey, J. C: Formation of cryolite and other aluminofluorides: A petrologic review. Bull. geol. Soc. Denmark, vol. 29, pp. 1-45. Copenhagen, June 10th, 1980.
  • Karaganda Region
    • Karkaraly
  • Oppland
    • Lunner
      • Nordmarka
Raade, G & Haug, J. (1980): Rare Fluorides from a soda granite in the Oslo Region, Norway. Mineralogical Record, 11,83-91
  • Buryatia
    • Mama River Basin
      • Maigunda River
Bailey, J. C: Formation of cryolite and other aluminofluorides: A petrologic review. Bull. geol. Soc. Denmark, vol. 29, pp. 1-45. Copenhagen, June 10th, 1980.
  • Tuva
no reference
Bailey, J. C: Formation of cryolite and other aluminofluorides: A petrologic review. Bull. geol. Soc. Denmark, vol. 29, pp. 1-45. Copenhagen, June 10th, 1980.
Seltmann, R., Soloviev, S., Shatov, V., Pirajno, F., Naumov, E., & Cherkasov, S. (2010). Metallogeny of Siberia: tectonic, geologic and metallogenic settings of selected significant deposits*. Australian Journal of Earth Sciences, 57(6), 655-706
  • Zabaykalsky Krai
    • Chitinskaya Oblast
Seltmann, R., Soloviev, S., Shatov, V., Pirajno, F., Naumov, E., & Cherkasov, S. (2010). Metallogeny of Siberia: tectonic, geologic and metallogenic settings of selected significant deposits*. Australian Journal of Earth Sciences, 57(6), 655-706; Sharygin, V. V., & Vladykin, N. V. (2014). Mineralogy of cryolite rocks from the Katugin massif, Transbaikalia, Russia. Abstract Book of 30th International Conference on “Ore Potential of Alkaline, Kimberlite and Carbonatite Magmatism,” Antalya, Turkey, 166-168.
Saudi Arabia
  • Mintaqah Tabuk
    • Midyan
Küster, D. (2009): Ore Geology Reviews 35, 68-86.
  • Washington
    • Okanogan Co.
      • Golden Horn Batholith
Micro Probe Volume VI Number 8; Rocks and Minerals, 66:6, p. 454
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