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Cupalite is an extremely rare copper-aluminum intermetallic mineral found primarily in placer deposits. It typically occurs as small, metallic grains with a distinct copper-steel-yellow color and is often only identifiable through specialized microscopic and chemical analysis.

Hardness
4.5
Mohs
Luster
Metallic
Streak
Copper-red
Transparency
Opaque

Is this cupalite?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

  • 1
    Test the hardness
    Try to scratch cupalite with a known reference. Cupalite sits at Mohs 4.5, softer than the next harder reference, harder than the previous one.
  • 2
    Check the streak
    Drag the specimen across an unglazed porcelain plate. Streak: copper-red.
  • 3
    Read the luster
    Hold the specimen under a strong light. Luster: metallic.
  • 4
    Match the color range
    Compare against the expected color range: steel yellow.
  • 5
    Look at form & habit
    Crystal system: orthorhombic. Typical habit: inclusions, microscopic crystals.

Often confused with

Cupalite vs. its common look-alikes, and how to tell them apart in the field.

Copper mineral
mineral
Copper
Mohs 2.5-3

How to tell apart: Cupalite is noticeably harder (Mohs 4.5 vs. 2.5-3); streak differs, so Cupalite leaves copper-red, Copper leaves rose.

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Often found alongside cupalite

Minerals reported to co-occur with cupalite. Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Chemical formula
CuAl
Mohs hardness
4.5
Density
5.12 g/cm³
Colors
Steel yellow
Streak
Copper-red
Luster
Metallic
Transparency
Opaque
Crystal system
Orthorhombic
Crystal habit
Inclusions, microscopic crystals
Cleavage
None
Rarity
Rare
Uses
Collector
Host rock
In black slick washed from greenish gray cover weathering from serpentine

Where rockhounds find cupalite

Classic worldwide localities

  • Listvenitovii stream, Khatirskii ultramafic zone of the Koryak-Kamchata fold area, Koryak Mountains, USSR

Field-hunting tip

Where it forms: In black slick washed from greenish gray cover weathering from serpentine. If you start seeing khatyrkite in float, you are in the right ground. Typical habit: inclusions, microscopic crystals. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify cupalite?+
Mohs hardness is 4.5. Luster: metallic. The streak is copper-red. Common colors include steel yellow.
Where is cupalite found?+
Notable localities include Listvenitovii stream, Khatirskii ultramafic zone of the Koryak-Kamchata fold area, Koryak Mountains, USSR.
Is cupalite safe to handle?+
Cupalite contains copper. Wash your hands afterwards, never grind or breathe the dust, and store it apart from specimens you handle often.
What rocks look like cupalite?+
Cupalite is most often confused with Copper. A quick hardness test and a streak check separate the look-alikes faster than color alone.
What minerals are found with cupalite?+
Cupalite commonly co-occurs with Khatyrkite. Spotting any of these in float or country rock is a useful trip signal.
What kind of rock does cupalite form in?+
Where it forms: In black slick washed from greenish gray cover weathering from serpentine. Working float back to the host body is the standard way to chase a fresh occurrence.
What is cupalite used for?+
Cupalite is used in collector.

Find cupalite on the map

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