Leverettite is a rare copper chloride hydroxide mineral, essentially a polymorph within the atacamite group. It is typically found as small, dark green platy crystals forming within the oxidation zones of copper ore bodies. Collectors primarily find it in specific historic copper mining localities, often requiring microscopic examination to distinguish from its more common group members.

Hardness
~3
Mohs
Luster
Vitreous
Streak
Light green
Transparency
Transparent

Is this leverettite?

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 leverettite with a known reference. Leverettite sits at Mohs ~3, softer than the next harder reference, harder than the previous one.
  • 2
    Check the streak
    Drag the specimen across an unglazed porcelain plate. Streak: light green.
  • 3
    Read the luster
    Hold the specimen under a strong light. Luster: vitreous.
  • 4
    Match the color range
    Compare against the expected color range: medium, deep green.
  • 5
    Look at form & habit
    Crystal system: trigonal. Typical habit: platy crystals, crusts, aggregates.

Often confused with

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

Often found alongside leverettite

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

All properties

Chemical formula
Cu₃CoCl₂(OH)₆
Mohs hardness
~3
Density
3.64 g/cm³
Colors
MediumDeep green
Streak
Light green
Luster
Vitreous
Transparency
Transparent
Crystal system
Trigonal
Crystal habit
Platy crystals, crusts, aggregates
Cleavage
Perfect on {101̄1}
Rarity
Rare
Uses
Collector
Host rock
As a secondary mineral in a weathered vein of copper and arsenic minerals

Where rockhounds find leverettite

Classic worldwide localities

  • Torrecillas mine, Salar Grande, Iquique Province, Tarapacá Region, Chile

Field-hunting tip

Where it forms: As a secondary mineral in a weathered vein of copper and arsenic minerals. If you start seeing akaganeite, anhydrite, chalcophanite in float, you are in the right ground. Typical habit: platy crystals, crusts, aggregates. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify leverettite?+
Mohs hardness is ~3. Luster: vitreous. The streak is light green. Common colors include medium, deep green.
Where is leverettite found?+
Notable localities include Torrecillas mine, Salar Grande, Iquique Province, Tarapacá Region, Chile.
Is leverettite safe to handle?+
Leverettite contains cobalt and copper. Contains copper and chlorine. Wash hands after handling; avoid inhaling dust or ingesting particles.
What rocks look like leverettite?+
Leverettite is most often confused with Atacamite, Paratacamite, Clinoatacamite. A quick hardness test and a streak check separate the look-alikes faster than color alone.
What minerals are found with leverettite?+
Leverettite commonly co-occurs with Akaganeite, Anhydrite, Chalcophanite, Goethite, Halite, Manganite. Spotting any of these in float or country rock is a useful trip signal.
What kind of rock does leverettite form in?+
Where it forms: As a secondary mineral in a weathered vein of copper and arsenic minerals. Working float back to the host body is the standard way to chase a fresh occurrence.
What is leverettite used for?+
Leverettite is used in collector.

Find leverettite on the map

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