pyrrhotite

enUK

pyr·rho·tite

P0691100 (pĭr′ə-tīt′) also pyr·rho·tine (-tīn′)n. A brownish-bronze iron sulfide mineral, FeS, characterized by weak magnetic properties and used as an iron ore and in the manufacture of sulfuric acid. Also called magnetic pyrites.

[Alteration (influenced by -ite) of German Pyrrhotin, from Greek purrotēs, redness, from purros, fiery, from pūr, fire; see paəwr̥ in Indo-European roots.]

pyrrhotite

(ˈpɪrəˌtaɪt) or

pyrrhotine

n (Minerals) a common bronze-coloured magnetic mineral consisting of ferrous sulphide in hexagonal crystalline form. Formula: FeS[C19: from Greek purrhotēs redness, from purrhos fiery, from pur fire]

pyr•rho•tite

(ˈpɪr əˌtaɪt)

n. a bronze-colored magnetic mineral, iron sulfide, occurring in massive and in crystal forms. [1868; < Greek pyrrhót(ēs) redness + -ite¹]

Thesaurus

Noun

pyrrhotite - a brownish iron sulfide mineral (FeS) having weak magnetic propertiesmagnetic pyrites, pyrrhotinemineral - solid homogeneous inorganic substances occurring in nature having a definite chemical composition

pyrrhotite

enUK

pyrrhotite

(pĭr`ətīt) or

magnetic pyrites,

bronze-yellow to bronze-red mineral, a sulfide of iron sometimes containing nickel. It tarnishes easily and is somewhat magnetic. It crystallizes in the hexagonal system, but appears usually in massive form, and occurs chiefly in basic igneous rocks. In some areas, e.g., at Sudbury, Ont., Canada, it is associated with pentlandite, an important ore of nickel. It is found also in the United States, Europe, and South America.

Pyrrhotite

(also pyrrhotine or magnetic pyrites), a sulfide mineral with composition Fe_1-xS and containing admixtures of Ni and Co. Pyrrhotite’s crystal structure has hexagonal close packing of S atoms. It is defective, since not all the octahedral vacancies are occupied by Fe, as a result which certain Fe²⁺ are converted to Fe³⁺. The structural deficiency in Fe varies, and thus the compositions range from Fe_0.875S (Fe₇S₈) to FeS (the stoichiometric composition FeS is known as troilite). The parameters and symmetry of the crystal cell vary according to the Fe deficiency and, when x ~ 0.11–0.2, pyrrhotite passes from the hexagonal modification to the monoclinic.

Pyrrhotite is brownish yellow with dark brown streaks and has a metallic luster. It usually occurs in the form of solid masses or granular deposits composed of intergrowths of both modifications. It has a hardness of 3.5–4.5 on Mohs’ scale and a density of 4,580–4,700 kg/m³. Its magnetic properties vary according to composition: hexagonal pyrrhotites, which are deficient in S, are paramagnetic, while monoclinic varieties, which are rich in S, are ferromagnetic. Some pyrrhotite minerals display distinctive magnetic anisotropy—paramagnetism in one direction and ferromagnetism in the other, perpendicular to the former.

Pyrrhotite is formed from hot solutions during a reduction in the concentration of dissociated S^2– ions. It is widely distributed in hypogenic copper-nickel ore deposits associated with ultrabasic rocks, as well as in contact-metasomatic deposits and hydrothermal masses with copper-polymetallic, sulfide-cassiterite, and other types of mineralization. Pyrrhotite alters to pyrite, marcasite, and limonite in the zone of oxidation.

REFERENCE

Mineraly, vol. 1, Moscow, 1960.

G. P. BARSANOV

pyrrhotite

[′pir·ə‚tīt] (mineralogy) Fe_1-xS A common reddish-brown to brownish-bronze mineral that occurs as rounded grains to large masses, more rarely as tabular pseudohexagonal crystals and rosettes; hardness is 4 on Mohs scale, and specific gravity is 4.6 (for the composition Fe₇S₈).

pyrrhotite

pyr·rho·tite

pyrrhotite

pyrrhotine

pyr•rho•tite

pyrrhotite

pyrrhotite

magnetic pyrites,

Pyrrhotite

REFERENCE

pyrrhotite

pyrrhotite

Synonyms for pyrrhotite

noun a brownish iron sulfide mineral (FeS) having weak magnetic properties

Synonyms

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