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 — 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 — 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 — that is 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.
