Melaconite is the earthy, powdery variety of tenorite, typically found as a black crust or soot-like deposit on copper ores. It forms in the supergene oxidized zones of copper-bearing deposits and is frequently associated with other secondary copper minerals like malachite and cuprite.
Is this melaconite?
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 melaconite with a known reference. Melaconite sits at Mohs 3, 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: dull.
- 4Match the color rangeCompare against the expected color range: black, gray.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: massive, powdery, or earthy coatings.
Often confused with
Melaconite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Luster reads dull on Melaconite and metallic on Pyrolusite.
How to tell apart: Luster reads dull on Melaconite and metallic on Tenorite.
How to tell apart: Streak differs, so Melaconite leaves black, Chalcocite leaves blackish lead-gray; luster reads dull on Melaconite and metallic on Chalcocite.
Often found alongside melaconite
Minerals reported to co-occur with melaconite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CuO
- Mohs hardness
- 3
- Density
- 6.4-6.5 g/cm³
- Streak
- Black
- Luster
- Dull
- Transparency
- Opaque
- Crystal system
- Monoclinic
- Crystal habit
- Massive, powdery, or earthy coatings
- Cleavage
- None
- Rarity
- Common
- Uses
- Collector, Ore of copper
- Host rock
- oxidized zones of copper deposits
Where rockhounds find melaconite
1 mapped spotsClassic worldwide localities
- Bisbee, Arizona, USA
- Chuquicamata, Chile
- Siegen, Germany
- Chessy-les-Mines, France
Field-hunting tip
Where it forms: oxidized zones of copper deposits. If you start seeing malachite, azurite, cuprite in float, you are in the right ground. Typical habit: massive, powdery, or earthy coatings. Train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Washington. Start trip planning there.
More melaconite photos
Common questions
How do you identify melaconite?+
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Can I find melaconite in the United States?+
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Find melaconite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
