Tenorite is a secondary copper oxide mineral typically found in the weathered oxidation zones of copper sulfide ore deposits. It is most commonly identified as a dull black, earthy, or metallic crust or powder coating other copper minerals like cuprite and malachite.
Is this tenorite?
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 tenorite with a known reference. Tenorite sits at Mohs 3-4, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Tenorite leaves a black streak.
- 3Read the lusterHold the specimen under a strong light. Tenorite typically shows a metallic luster.
- 4Match the color rangeCompare against the expected color range: black, gray.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: massive, earthy, botryoidal, or thin scales.
Often confused with
Tenorite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Pyrolusite is the harder of the two (Mohs 6-6.5 vs. 3-4).
How to tell apart: Iron Ore is the harder of the two (Mohs 5-6.5 vs. 3-4); streak differs, so Tenorite leaves black, Iron Ore leaves reddish-brown to black; luster reads metallic on Tenorite and metallic to submetallic on Iron Ore.
How to tell apart: Streak differs, so Tenorite leaves black, Manganite leaves dark reddish-brown; luster reads metallic on Tenorite and submetallic on Manganite.
Often found alongside tenorite
Minerals reported to co-occur with tenorite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CuO
- Mohs hardness
- 3-4
- Density
- 6.4-6.5 g/cm³
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Monoclinic
- Crystal habit
- Massive, Earthy, Botryoidal, Or Thin Scales
- Cleavage
- Good
- Rarity
- Common
- Uses
- Collector, Ore of Copper
- Host rock
- Oxidized Zones of Copper Deposits
- Typical price
- $10-60 for small mineral specimens
Where rockhounds find tenorite
2 mapped spotsClassic worldwide localities
- Vesuvius, Italy
- Bisbee, Arizona, USA
- Chuquicamata, Chile
- Copper Queen Mine, Arizona, USA
Field-hunting tip
Look in oxidized zones of copper deposits country, the host setting where tenorite typically forms. If you start seeing cuprite, chrysocolla, malachite in float, you are in the right ground. Field specimens usually show a massive, earthy, botryoidal, or thin scales habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Arizona, Utah. Start trip planning there.
Common questions
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Find tenorite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
