Tripuhyite
Tripuhyite | |
---|---|
General | |
Category | Antimonate mineral |
Formula (repeating unit) | FeSbO4 |
IMA symbol | Tpy[1] |
Strunz classification | 4.DB.05 |
Crystal system | Tetragonal |
Crystal class | Ditetragonal dipyramidal (4/mmm) H-M symbol: (4/m 2/m 2/m) |
Space group | P41/mnm |
Unit cell | a = 4.63, c = 9.14 [Å]; Z = 2 |
Identification | |
Color | Yellowish brown, lemon-yellow, brown-black |
Crystal habit | Fibrous to fine-grained aggregates |
Mohs scale hardness | 6 - 7 |
Luster | Dull to earthy |
Streak | Canary-yellow to dark brown with a greenish tinge |
Diaphaneity | Translucent |
Specific gravity | 5.82 |
Optical properties | Uniaxial (+), canary-yellow color (transmitted light) |
Refractive index | nω = 2.190 nε = 2.330 |
Birefringence | δ = 0.140 |
Pleochroism | None |
Solubility | Insoluble in acids |
Other characteristics | Antiferromagnetic |
References | [2][3][4] |
Tripuhyite is an iron antimonate mineral with composition FeSbO4.
Nomenclature
[edit]The name of the mineral comes from the locality of Tripuhy, Ouro Preto, Minas Gerais, Brazil, where it was discovered. Hussak and Prior[5] first described the mineral tripuhyite as an oxide of iron and antimony, and assigned it the composition Fe2Sb2O7. When a mineral with composition FeSbO4 was later discovered in Squaw Creek, New Mexico (US), it was considered erroneously as a new mineral and it was given the name squawcreekite.[6] However, other studies had shown that the original tripuhyite was also FeSbO4.[7] In 2002, the Commission on New Minerals and Mineral Names (CNMMN) of the International Mineralogical Association (IMA), approved the redefinition of tripuhyite as FeSbO4 and the discreditation of squawcreekite.[8]
Crystal Structure
[edit]FeSbO4 exhibits the rutile structure, with a tetragonal unit cell. The cations are octahedrally coordinated to oxygen anions, with the octahedra sharing edges along the c-direction. Fe(III) and Sb(V) cations are distributed in a disordered way over the octahedral sites.
References
[edit]- ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
- ^ Mindat.org
- ^ Handbook of Mineralogy
- ^ Webmineral data
- ^ Hussak, E.; Prior, G. T. (1897). "On Tripuhyite, a New Antimonate of Iron, from Tripuhy, Brazil". Mineralogical Magazine. 11 (53): 302–303. Bibcode:1897MinM...11..302H. doi:10.1180/minmag.1897.011.53.04.
- ^ Foord, E. E.; P. F. Hlava; J. J. Fitzpatrick; R. C. Erd; R. W. Hinton (1991). Neues Jahrbuch für Mineralogie - Monatshefte. 8: 363–384.
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(help) - ^ Tavora, E. (1955). "X-ray diffraction powder data for some minerals from Brazilian localities". Anais da Academia Brasileira de Ciências. 27: 7–27.
- ^ Berlepsch, P.; T. Armbruster; J. Brugger; A. J. Criddle; S. Graeser (2003). "Tripuhyite, FeSbO4, revisited". Mineralogical Magazine. 67 (1): 31–46. Bibcode:2003MinM...67...31B. doi:10.1180/0026461036710082. S2CID 54551345.
Bibliography
[edit]- Palache, P.; Berman H.; Frondel, C. (1960). "Dana's System of Mineralogy, Volume II: Halides, Nitrates, Borates, Carbonates, Sulfates, Phosphates, Arsenates, Tungstates, Molybdates, Etc. (Seventh Edition)" John Wiley and Sons, Inc., New York, pp. 1024.