Tripuhyite is an
iron
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in f ...
antimonate mineral
Antimonate minerals are those minerals containing the antimonate (SbO43−) anion group. Both the Dana and the Strunz mineral classifications place the antimonates in with the phosphate minerals
Phosphate minerals contain the tetrahedrally coord ...
with composition FeSbO
4.
Nomenclature
The name of the mineral comes from the locality of Tripuhy,
Ouro Preto
Ouro Preto (, ''Black Gold''), formerly Vila Rica (, ''Rich Village''), is a city in and former capital of the state of Minas Gerais, Brazil, a former colonial mining town located in the Serra do Espinhaço mountains and designated a World Herita ...
, Minas Gerais, Brazil, where it was discovered. Hussak and Prior first described the mineral tripuhyite as an oxide of
iron
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in f ...
and
antimony
Antimony is a chemical element with the symbol Sb (from la, stibium) and atomic number 51. A lustrous gray metalloid, it is found in nature mainly as the sulfide mineral stibnite (Sb2S3). Antimony compounds have been known since ancient time ...
, and assigned it the composition Fe
2Sb
2O
7. When a mineral with composition FeSbO
4 was later discovered in Squaw Creek, New Mexico (US), it was considered erroneously as a new mineral and it was given the name ''squawcreekite''. However, other studies had shown that the original tripuhyite was also FeSbO
4. In 2002, the Commission on New Minerals and Mineral Names (CNMMN) of the
International Mineralogical Association
Founded in 1958, the International Mineralogical Association (IMA) is an international group of 40 national societies. The goal is to promote the science of mineralogy and to standardize the nomenclature of the 5000 plus known mineral species. Th ...
(IMA), approved the redefinition of tripuhyite as FeSbO
4 and the discreditation of squawcreekite.
Crystal Structure
FeSbO
4 exhibits the
rutile
Rutile is an oxide mineral composed of titanium dioxide (TiO2), the most common natural form of TiO2. Rarer Polymorphism (materials science), polymorphs of TiO2 are known, including anatase, akaogiite, and brookite.
Rutile has one of the highest ...
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
Bibliography
*
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.
Tetragonal minerals
Iron(III) minerals
Antimony minerals
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