Chalcopyrite is the most important copper ore mineral, easily identified by its brass-yellow color and tendency to tarnish with iridescent blues, purples, and greens. It is commonly mistaken for pyrite, but it is softer and has a distinctive greenish-black streak. Collectors prize specimens for their bright metallic luster and frequent association with other sulfide minerals.
Is this chalcopyrite?
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 chalcopyrite with a known reference. Chalcopyrite sits at Mohs 3.5-4 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Chalcopyrite leaves a greenish-black streak.
- 3Read the lusterHold the specimen under a strong light. Chalcopyrite typically shows a metallic luster.
- 4Match the color rangeCompare against the expected color range: brass-yellow, iridescent, gold.
- 5Look at form & habitCrystal system: tetragonal. Typical habit: tetrahedral crystals, massive, botryoidal.
Often confused with
Chalcopyrite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Pyrite is the harder of the two (Mohs 6-6.5 vs. 3.5-4); streak differs — Chalcopyrite leaves greenish-black, Pyrite leaves greenish-black to brownish-black.
How to tell apart: Streak differs — Chalcopyrite leaves greenish-black, Bornite leaves greyish black.
How to tell apart: Streak differs — Chalcopyrite leaves greenish-black, Pyrrhotite leaves dark grey to black.
Often found alongside chalcopyrite
Minerals reported to co-occur with chalcopyrite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CuFeS₂
- Mohs hardness
- 3.5-4
- Density
- 4.1-4.3 g/cm³
- Streak
- Greenish-black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Tetragonal
- Crystal habit
- Tetrahedral Crystals, Massive, Botryoidal
- Cleavage
- Indistinct
- Rarity
- Common
- Uses
- Ore, Collector, Specimen
- Host rock
- Hydrothermal Veins, Igneous, Metamorphic, And Sedimentary Deposits
- Typical price
- $5-50 thumbnail, $20-200 cabinet
Where rockhounds find chalcopyrite
117 mapped spotsClassic worldwide localities
- Chuquicamata, Chile
- Mount Lyell, Australia
- Kennecott, USA
- Rio Tinto, Spain
- Dzhezkazgan, Kazakhstan
U.S. states with chalcopyrite
Each link opens a state-specific list of mapped rockhounding spots that produce chalcopyrite.
- Utah27 spots
- Missouri14 spots
- New Mexico7 spots
- Massachusetts6 spots
- North Carolina6 spots
- Pennsylvania5 spots
- Virginia5 spots
Field-hunting tip
Look in hydrothermal veins, igneous, metamorphic, and sedimentary deposits country — that is the host setting where chalcopyrite typically forms. If you start seeing pyrite, sphalerite, galena in float, you are in the right ground. Field specimens usually show a tetrahedral crystals, massive, botryoidal habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Utah, Missouri, New Mexico — start trip planning there.
Common questions
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Find chalcopyrite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
