Tetrataenite is an ordered iron-nickel alloy found primarily within the metal phases of iron meteorites. It is highly prized by collectors for its unique magnetic properties and its occurrence as thin, lamellar bands formed through long-term cooling in extraterrestrial bodies.
Is this tetrataenite?
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 tetrataenite with a known reference. Tetrataenite sits at Mohs 3.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: gray.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic.
- 4Match the color rangeCompare against the expected color range: silver white, gray white.
- 5Look at form & habitCrystal system: tetragonal. Typical habit: exsolution inclusions, granular, massive.
Often confused with
Tetrataenite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Taenite is the harder of the two (Mohs 5-5.5 vs. 3.5); streak differs, so Tetrataenite leaves gray, Taenite leaves light gray.
How to tell apart: Schreibersite is the harder of the two (Mohs 6.5-7 vs. 3.5); streak differs, so Tetrataenite leaves gray, Schreibersite leaves dark gray; luster reads metallic on Tetrataenite and brilliant metallic on Schreibersite.
Often found alongside tetrataenite
Minerals reported to co-occur with tetrataenite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- FeNi
- Mohs hardness
- 3.5
- Density
- 8.275 g/cm³
- Colors
- Streak
- Gray
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Tetragonal
- Crystal habit
- Exsolution inclusions, granular, massive
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector, Scientific research
- Host rock
- In slowly cooled meteorites, by the ordering of Fe and Ni atoms in taenite
Where rockhounds find tetrataenite
Classic worldwide localities
- Pokphur magnetite body, north-eastern most part of the Nagaland-Manipur ophiolite belt, Indo-Myanmar ranges, northeast India
Field-hunting tip
Where it forms: In slowly cooled meteorites, by the ordering of Fe and Ni atoms in taenite. If you start seeing kamacite, troilite, taenite in float, you are in the right ground. Typical habit: exsolution inclusions, granular, massive. Train your eye for that shape before scanning the outcrop.
Common questions
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Find tetrataenite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
