Stibiocolusite is a rare member of the colusite series, typically found as microscopic grains within complex sulfide ores. It is distinguished from similar sulfosalts primarily through electron microprobe analysis rather than visual observation due to its massive habit and metallic grey color.
Is this stibiocolusite?
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 stibiocolusite with a known reference. Stibiocolusite sits at Mohs 4-4.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: black.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic.
- 4Match the color rangeCompare against the expected color range: bronze.
- 5Look at form & habitCrystal system: hexagonal. Typical habit: anhedral to subhedral grains.
Often confused with
Stibiocolusite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Stibiocolusite leaves black, Germanite leaves dark gray to black.
How to tell apart: Streak differs, so Stibiocolusite leaves black, Tennantite leaves reddish gray.
Often found alongside stibiocolusite
Minerals reported to co-occur with stibiocolusite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Cu₁₂CuV(Sb,Sn,As)₃S₁₆
- Mohs hardness
- 4-4.5
- Density
- 10.8 g/cm³
- Colors
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Hexagonal
- Crystal habit
- Anhedral to subhedral grains
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- An uncommon constituent of PGE deposits in layered intrusives and ophiolites, nevertheless a major carrier of palladium; in placers
Where rockhounds find stibiocolusite
Classic worldwide localities
- Goodnews Bay, Alaska, USA
- Transvaal, South Africa, from Tweefontein Farm, Potgietersrus district (type locality), and from the Elephant Winze, near Rietfontein
- Onverwacht and Driekop mines, all on the Merensky Reef, Bushveld complex
- Morozova mine, Noril’sk region, western Siberia, Russia
- Zlatoust, Ural Mountains, Russia
- Pustaya River placers, Kamchatka, Russia
Field-hunting tip
Where it forms: An uncommon constituent of PGE deposits in layered intrusives and ophiolites, nevertheless a major carrier of palladium; in placers. If you start seeing braggite, cooperite, mertieite-ii in float, you are in the right ground. Typical habit: anhedral to subhedral grains. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify stibiocolusite?+
Where is stibiocolusite found?+
Is stibiocolusite safe to handle?+
What rocks look like stibiocolusite?+
What minerals are found with stibiocolusite?+
What kind of rock does stibiocolusite form in?+
What is stibiocolusite used for?+
Find stibiocolusite on the map
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