Troilite is a rare terrestrial sulfide, though it is the most common sulfide mineral found in iron meteorites. It typically occurs as bronze-colored, non-magnetic massive grains embedded within meteoritic iron-nickel alloys. Collectors primarily find this mineral as distinct inclusions within curated meteorite specimens rather than as individual terrestrial crystal specimens.
Is this troilite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch troilite with a known reference. Troilite sits at Mohs 3.5-4 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Troilite leaves a black streak.
- 3Read the lusterHold the specimen under a strong light. Troilite typically shows a metallic luster.
- 4Match the color rangeCompare against the expected color range: bronze, brownish-bronze, yellowish-brown.
- 5Look at form & habitCrystal system: hexagonal. Typical habit: massive, granular, or as inclusions in meteorites.
Often confused with
Troilite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Streak differs — Troilite leaves black, Pyrrhotite leaves dark grey to black.
How to tell apart: Streak differs — Troilite leaves black, Pentlandite leaves light bronze-brown.
How to tell apart: Pyrite is the harder of the two (Mohs 6-6.5 vs. 3.5-4); streak differs — Troilite leaves black, Pyrite leaves greenish-black to brownish-black.
Often found alongside troilite
Minerals reported to co-occur with troilite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- FeS
- Mohs hardness
- 3.5-4
- Density
- 4.6-4.8 g/cm³
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Hexagonal
- Crystal habit
- Massive, Granular, Or as Inclusions in Meteorites
- Cleavage
- None
- Rarity
- Uncommon
- Uses
- Collector, Meteorite Study
- Host rock
- Meteorites, Lunar Samples, And Rare Terrestrial Mafic/ultramafic Rocks
- Typical price
- $20-200 depending on specimen size and meteorite provenance
Where rockhounds find troilite
Classic worldwide localities
- Moon
- Canyon Diablo meteorite (Arizona, USA)
- Various iron meteorites
- Bushveld Complex (South Africa)
Field-hunting tip
Look in meteorites, lunar samples, and rare terrestrial mafic/ultramafic rocks country — that is the host setting where troilite typically forms. If you start seeing kamacite, taenite, schreibersite in float, you are in the right ground. Field specimens usually show a massive, granular, or as inclusions in meteorites habit, so train your eye for that shape before scanning the outcrop.
Common questions
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Find troilite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
