Trüstedtite is a rare nickel selenide mineral belonging to the thiospinel group. It typically occurs as opaque, metallic grains within sulfide-rich ore deposits and is most commonly identified through laboratory analysis of its selenium content.
Is this trüstedtite?
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 trüstedtite with a known reference. Trüstedtite sits at Mohs ~2.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: grayish-black.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic.
- 4Match the color rangeCompare against the expected color range: yellow.
- 5Look at form & habitCrystal system: cubic. Typical habit: euhedral crystals, inclusions.
Often confused with
Trüstedtite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Linnaeite is the harder of the two (Mohs 4.5-5.5 vs. ~2.5); streak differs, so Trüstedtite leaves grayish-black, Linnaeite leaves grayish black.
How to tell apart: Polydymite is the harder of the two (Mohs 4.5-5.5 vs. ~2.5); streak differs, so Trüstedtite leaves grayish-black, Polydymite leaves black gray.
Often found alongside trüstedtite
Minerals reported to co-occur with trüstedtite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ni₃Se₄
- Mohs hardness
- ~2.5
- Density
- 6.62 g/cm³
- Colors
- Streak
- Grayish-black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Cubic
- Crystal habit
- Euhedral crystals, inclusions
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In uranium-bearing calcite veins in sills of albite diabase in schist (Kuusamo, Finland); in stibnite-quartz-barite veins in schists (Qiongmo deposit, China)
Where rockhounds find trüstedtite
Classic worldwide localities
- Kuusamo, northeastern Finland (type locality)
- Qiongmo gold deposit, western Qinling Mountains, Shaanxi Province, China
Field-hunting tip
Where it forms: In uranium-bearing calcite veins in sills of albite diabase in schist (Kuusamo, Finland); in stibnite-quartz-barite veins in schists (Qiongmo deposit, China). If you start seeing clausthalite, penroseite, sederholmite in float, you are in the right ground. Typical habit: euhedral crystals, inclusions. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify trüstedtite?+
Where is trüstedtite found?+
Is trüstedtite safe to handle?+
What rocks look like trüstedtite?+
What minerals are found with trüstedtite?+
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Find trüstedtite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
