Delafossite is a rare copper-iron oxide mineral typically found in the oxidized zones of copper deposits. It commonly presents as dark, metallic-looking tabular or hexagonal crystals that can easily be mistaken for hematite but are softer and less dense.
Is this delafossite?
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 delafossite with a known reference. Delafossite sits at Mohs 5.5, 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: metallic.
- 4Match the color rangeCompare against the expected color range: black.
- 5Look at form & habitCrystal system: trigonal. Typical habit: crystalline, tabular.
Often confused with
Delafossite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Delafossite leaves black, Hematite leaves cherry-red or reddish brown.
How to tell apart: Streak differs, so Delafossite leaves black, Goethite leaves brownish yellow, yellow-orange, ocher-yellow; luster reads metallic on Delafossite and imperfect adamantine metallic to dull earthy; silky when fibrous on Goethite.
How to tell apart: Delafossite is noticeably harder (Mohs 5.5 vs. 3.5).
Often found alongside delafossite
Minerals reported to co-occur with delafossite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CuFeO₂
- Mohs hardness
- 5.5
- Density
- 5.41 g/cm³
- Colors
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Trigonal
- Crystal habit
- Crystalline, tabular
- Cleavage
- {1011}, imperfect
- Rarity
- Rare
- Uses
- Collector, Scientific research
- Host rock
- Principally as a secondary mineral near the base of the oxidized zone of copper deposits; less commonly a primary mineral
Where rockhounds find delafossite
Classic worldwide localities
- Bisbee, Cochise Co., and in the United Verde mine, Jerome, Yavapai Co., Arizona, USA
- Alpha mine, Kimberly, White Pine Co., and Eureka, Eureka Co., Nevada, USA
- Salmon, Lemhi Co., Idaho, USA
- Kirwin mineralized area, Park Co., Wyoming, USA
- Mednorudyanskoye copper deposit, Nizhni Tagil, near Yekaterinburg (Sverdlovsk), Ural Mountains, Russia
- Cartagenera mine, near Pedroso, Sevilla, Spain
Field-hunting tip
Where it forms: Principally as a secondary mineral near the base of the oxidized zone of copper deposits; less commonly a primary mineral. If you start seeing cuprite, copper, tenorite in float, you are in the right ground. Typical habit: crystalline, tabular. Train your eye for that shape before scanning the outcrop.
Common questions
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Find delafossite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
