Harmunite is an extremely rare calcium iron oxide mineral identified primarily in high-temperature pyrometamorphic rocks. It typically appears as small yellow to yellowish-black crystals within complex mineral assemblages formed by combustion metamorphism.
Is this harmunite?
3-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 harmunite with a known reference. Harmunite sits at Mohs 5.5, softer than the next harder reference, harder than the previous one.
- 2Match the color rangeCompare against the expected color range: black.
- 3Look at form & habitCrystal system: orthorhombic. Typical habit: platy to tabular crystals.
Often confused with
Harmunite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside harmunite
Minerals reported to co-occur with harmunite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CaFe₂O₄
- Mohs hardness
- 5.5
- Density
- 4.404 g/cm³
- Colors
- Transparency
- Opaque
- Crystal system
- Orthorhombic
- Crystal habit
- Platy to tabular crystals
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In pyrometamorphic larnite pebbles of a pseudo-conglomerate, the cement of which consists of intensely altered larnite-bearing rocks, likely formed in the presence of sulfate melt
Where rockhounds find harmunite
Classic worldwide localities
- Hatrurim Complex, southern slope of Jabel (Mt.) Harmun, Judean Desert, West Bank, Palestinian Autonomy, Israel
Field-hunting tip
Where it forms: In pyrometamorphic larnite pebbles of a pseudo-conglomerate, the cement of which consists of intensely altered larnite-bearing rocks, likely formed in the presence of sulfate melt. If you start seeing srebrodolskite, magnesioferrite, larnite in float, you are in the right ground. Typical habit: platy to tabular crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify harmunite?+
Where is harmunite found?+
What rocks look like harmunite?+
What minerals are found with harmunite?+
What kind of rock does harmunite form in?+
What is harmunite used for?+
Find harmunite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
