Polished and etched surface of the Mundrabilla meteorite from Australia. The darker brownish areas with striations are troilite with exolved daubréelite.
General
Category
Sulfide mineral
Formula (repeating unit)
FeS
IMA symbol
Tro[1]
Strunz classification
2.CC.10
Crystal system
Hexagonal
Crystal class
Ditrigonal dipyramidal (6m2) H-M symbol: (6m2)
Space group
P62c
Unit cell
a = 5.958, c = 11.74 [Å]; Z = 12
Identification
Color
Pale gray brown
Crystal habit
Massive, granular; nodular; platey to tabular
Cleavage
None
Fracture
Irregular
Mohs scale hardness
3.5–4.0
Luster
Metallic
Streak
Gray black
Diaphaneity
Opaque
Specific gravity
4.67–4.79
Alters to
Tarnishes on exposure to air
References
[2][3][4]
Troilite is a rare iron sulfide mineral with the simple formula of FeS. It is the iron-rich endmember of the pyrrhotite group. Pyrrhotite has the formula Fe(1-x)S (x = 0 to 0.2) which is iron deficient. As troilite lacks the iron deficiency which gives pyrrhotite its characteristic magnetism, troilite is non-magnetic.[3]
Troilite can be found as a native mineral on Earth but is more abundant in meteorites, in particular, those originating from the Moon and Mars. It is among the minerals found in samples of the meteorite that struck Russia in Chelyabinsk on February 15th, 2013.[5] Uniform presence of troilite on the Moon and possibly on Mars has been confirmed by the Apollo, Viking and Phobos space probes. The relative intensities of isotopes of sulfur are rather constant in meteorites as compared to the Earth minerals, and therefore troilite from Canyon Diablo meteorite is chosen as the international sulfur isotope ratio standard, the Canyon Diablo Troilite (CDT).
Troilite is a rare iron sulfide mineral with the simple formula of FeS. It is the iron-rich endmember of the pyrrhotite group. Pyrrhotite has the formula...
(cubic) Pyrrhotite, Fe1−xS (where x = 0 to 0.2) (monoclinic or hexagonal) Troilite, FeS, the endmember of pyrrhotite (hexagonal) Mackinawite, Fe1+xS (where...
example, "ferrous sulfide" can refer to the 1:1 species (mineral name troilite) or a host of Fe-deficient derivatives (pyrrhotite). The mineral magnetite...
0.125). It is a nonstoichiometric variant of FeS, the mineral known as troilite. Pyrrhotite is also called magnetic pyrite, because the color is similar...
metal and troilite, small oxide veins. W2: moderate oxidation of metal (about 20-60% replaced). W3: heavy oxidation of metal and troilite (60-95% replaced)...
and contained enstatite, kamacite, niningerite, silica, schreibersite, troilite, albite, and daubréelite. It is classed as an enstatite chondrite (EH)...
often form rounded nodules of troilite or graphite, surrounded by schreibersite and cohenite. Schreibersite and troilite also occur as plate shaped inclusions...
20 mol%. They contain also 15–19% of nickel-iron metal and about 5% of troilite. The majority of these meteorites have been significantly metamorphosed...
olivine and hypersthene (an orthopyroxene), as well as iron–nickel and troilite. Chromite, sodium-rich feldspar and calcium phosphates occur in minor amounts...
belongs to the chemical group IIIAB. There are abundant elongated troilite nodules. The troilite nodules contain inclusions of chromite, sulfides, phosphates...
are hypersthene (a pyroxene) and olivine. Other minerals include Fe–Ni, troilite (FeS), feldspar or feldspathic glass, chromite, and phosphates. LL chondrites...
iron, lead, limestone, mercury, mirabilite, nickel, crude oil, platinum, troilite, tungsten, and zinc among others. The oil fields at Yumen and Changqing...
Mexico, Canada, Brazil, and Madagascar. In meteorites, graphite occurs with troilite and silicate minerals. Small graphitic crystals in meteoritic iron are...
They contain low-Ca pyroxene, high-Ca pyroxene, olivine, plagioclase, troilite, graphite, different phosphates, meteoric iron and traces of daubréelite...
orthopyroxene, or enstatite, with minor phases of olivine, nickel-iron metal, and troilite, indicating a magmatic formation under extremely reducing conditions. The...
Kassel in Germany. Associated minerals include native iron, schreibersite, troilite and wustite. Similar iron carbides occur also in technical iron alloys...
particularly rare type of meteorite that contains sulfide minerals (particularly troilite, FeS), metallic nickel-iron alloys, plus silicate minerals. This is important...
carbonaceous chondrites may contain as much as 6.6%. It is normally present as troilite (FeS), but there are exceptions, with carbonaceous chondrites containing...
also common in iron meteorites and form in association with silicates and troilite minerals. The chemical composition of chromite can be represented as FeCr2O4...
American meteorite collector. The mineral is typically found intermixed with troilite, an iron sulfide. It is a minor constituent of metal enstatite chondrite...
primarily composed of olivine, orthopyroxene, plagioclase, meteoric iron, and troilite. Like all primitive achondrites, acapulcoites have chemical composition...
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