Chlorbartonite is a rare potassium iron sulfide chloride mineral discovered in alkaline massifs. It typically appears as dark green to black submetallic grains or platy crystals often found within the core of magnetite-rich rocks. Collectors prize it for its unique chemical composition related to the baronite group.
Is this chlorbartonite?
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 chlorbartonite with a known reference. Chlorbartonite sits at Mohs 4, 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: submetallic.
- 4Match the color rangeCompare against the expected color range: brown, black.
- 5Look at form & habitCrystal system: tetragonal. Typical habit: anhedral grains, inclusions.
Often confused with
Chlorbartonite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside chlorbartonite
Minerals reported to co-occur with chlorbartonite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- K₆Fe₂₄S₂₆Cl
- Mohs hardness
- 4
- Density
- 3.70 g/cm³
- Streak
- Black
- Luster
- Submetallic
- Transparency
- Opaque
- Crystal system
- Tetragonal
- Crystal habit
- Anhedral grains, inclusions
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In an alkaline hydrothermal vein in feldspathic urtite within apatite-nepheline rock
Where rockhounds find chlorbartonite
Classic worldwide localities
- Mount Koashva, Khibina massif, Kola Peninsula, Russia
Field-hunting tip
Where it forms: In an alkaline hydrothermal vein in feldspathic urtite within apatite-nepheline rock. If you start seeing djerfisherite, rasvumite, microcline in float, you are in the right ground. Typical habit: anhedral grains, inclusions. Train your eye for that shape before scanning the outcrop.
Common questions
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Find chlorbartonite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
