Cobaltpentlandite is a rare cobalt-dominant sulfide mineral within the pentlandite group. It typically appears as metallic, bronze-yellow granular masses in hydrothermal mineral deposits and is primarily sought after by advanced systematic collectors.
Is this cobaltpentlandite?
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 cobaltpentlandite with a known reference. Cobaltpentlandite sits at Mohs 4-5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: brownish-bronze.
- 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: massive, granular, or anhedral grains.
Often confused with
Cobaltpentlandite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Cobaltpentlandite leaves brownish-bronze, Pentlandite leaves pale bronze-brown.
How to tell apart: Streak differs, so Cobaltpentlandite leaves brownish-bronze, Pyrrhotite leaves dark grayish black.
How to tell apart: Streak differs, so Cobaltpentlandite leaves brownish-bronze, Linnaeite leaves grayish black.
Often found alongside cobaltpentlandite
Minerals reported to co-occur with cobaltpentlandite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Co₉S₈
- Mohs hardness
- 4-5
- Density
- 5.22 g/cm³
- Colors
- Streak
- Brownish-bronze
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Cubic
- Crystal habit
- Massive, granular, or anhedral grains
- Cleavage
- {100}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- With other sulfides and arsenides in hydrothermal deposits
Where rockhounds find cobaltpentlandite
Classic worldwide localities
- Varislahti (type locality), Kuusjärvi, and Savonranta pyrrhotite deposits and in the Outokumpu mine, northern Karelia, Finland
- Långban, Värmland, Sweden
- Vı̂lsan, Romania
- Langis mine, Casey Township, Cobalt-Gowganda area, Ontario, and the Vauze mine, north of Noranda, Quebec, Canada
- Salamanca mine, Mendoza Province, Argentina
- Amianthus mine, Kaapsche Hoop, Barberton, and the Loolekop carbonatite, Phalaborwa, Transvaal, South Africa
Field-hunting tip
Where it forms: With other sulfides and arsenides in hydrothermal deposits. If you start seeing pyrite, marcasite, pyrrhotite in float, you are in the right ground. Typical habit: massive, granular, or anhedral grains. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify cobaltpentlandite?+
Where is cobaltpentlandite found?+
Is cobaltpentlandite safe to handle?+
What rocks look like cobaltpentlandite?+
What minerals are found with cobaltpentlandite?+
What kind of rock does cobaltpentlandite form in?+
What is cobaltpentlandite used for?+
Find cobaltpentlandite on the map
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