Barlowite is a rare copper halide mineral first identified in the oxidation zone of copper deposits in Chile. It typically forms deep blue tabular crystals that are highly sought after by mineral collectors for their unique structure and vibrant color.

Hardness

2-2.5

Mohs

Luster

Vitreous

Streak

Sky-blue

Transparency

Transparent to translucent

mineralrareHerbertsmithite Group family

Barlowite

Hardness: 2-2.5
Luster: Vitreous
Streak: Sky-blue
Transparency: Transparent to translucent

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Is this barlowite?

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 barlowite with a known reference. Barlowite sits at Mohs 2-2.5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: sky-blue.
3
Read the luster
Hold the specimen under a strong light. Luster: vitreous.
4
Match the color range
Compare against the expected color range: blue.
5
Look at form & habit
Crystal system: hexagonal. Typical habit: tabular crystals, subparallel aggregates.

Often confused with

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

How to tell apart: Streak differs, so Barlowite leaves sky-blue, Paratacamite leaves green.

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Often found alongside barlowite

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

All properties

Chemical formula: Cu₄Br(OH)₆F
Mohs hardness: 2-2.5
Density: 4.21 g/cm³
Colors: Blue
Streak: Sky-blue
Luster: Vitreous
Transparency: Transparent to translucent
Crystal system: Hexagonal
Crystal habit: Tabular crystals, subparallel aggregates
Cleavage: Perfect on {0001}
Rarity: Rare
Uses: Collector
Host rock: A secondary mineral in the weathering zone of a copper deposit

Where rockhounds find barlowite

Classic worldwide localities

Great Australia mine, 2 km south of Cloncurry, northwest Queensland, Australia

Field-hunting tip

Where it forms: A secondary mineral in the weathering zone of a copper deposit. If you start seeing gerhardtite, brochantite, cuprite in float, you are in the right ground. Typical habit: tabular crystals, subparallel aggregates. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify barlowite?+

Mohs hardness is 2-2.5. Luster: vitreous. The streak is sky-blue. Common colors include blue.

Where is barlowite found?+

Notable localities include Great Australia mine, 2 km south of Cloncurry, northwest Queensland, Australia.

Is barlowite safe to handle?+

Barlowite contains copper. Contains copper; handle with care and wash hands after handling to avoid ingestion or skin irritation.

What rocks look like barlowite?+

Barlowite is most often confused with Herbertsmithite, Paratacamite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with barlowite?+

Barlowite commonly co-occurs with Gerhardtite, Brochantite, Cuprite, Quartz, Goethite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does barlowite form in?+

Where it forms: A secondary mineral in the weathering zone of a copper deposit. Working float back to the host body is the standard way to chase a fresh occurrence.

What is barlowite used for?+

Barlowite is used in collector.

Find barlowite on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.