Liroconite is a highly sought-after secondary copper mineral, famous for its intense sky-blue to deep green color and distinctively flattened, wedge-shaped crystals. It is primarily found in the oxidized zones of copper-arsenic deposits, historically reaching its finest aesthetic development in the mines of Cornwall, England.

Hardness

2-2.5

Mohs

Luster

Vitreous to resinous

Streak

Pale blue to pale green

Transparency

Transparent to translucent

mineralrare

Liroconite

Hardness: 2-2.5
Luster: Vitreous to resinous
Streak: Pale blue to pale green
Transparency: Transparent to translucent

Is this liroconite?

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 liroconite with a known reference. Liroconite 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: pale blue to pale green.
3
Read the luster
Hold the specimen under a strong light. Luster: vitreous to resinous.
4
Match the color range
Compare against the expected color range: sky blue, light blue, green, verdigris green.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: euhedral crystals, granular.

Often confused with

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

How to tell apart: Streak differs, so Liroconite leaves pale blue to pale green, Clinoclase leaves bluish green.

How to tell apart: Streak differs, so Liroconite leaves pale blue to pale green, Aurichalcite leaves light blue; luster reads vitreous to resinous on Liroconite and silky to pearly on Aurichalcite.

Compare →

Often found alongside liroconite

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

All properties

Chemical formula: Cu₂Al(AsO₄)(OH)₄·4H₂O
Mohs hardness: 2-2.5
Density: 2.94-3.01 g/cm³
Colors: Sky blue Light blue GreenVerdigris green
Streak: Pale blue to pale green
Luster: Vitreous to resinous
Transparency: Transparent to translucent
Crystal system: Monoclinic
Crystal habit: Euhedral crystals, granular
Cleavage: On {110}, {011}, indistinct
Rarity: Rare
Uses: Collector
Host rock: A rare secondary mineral in the oxidized zone of some copper deposits

Where rockhounds find liroconite

Classic worldwide localities

Sterling Hill, Ogdensburg, Sussex Co., New Jersey, and at Bisbee, Cochise Co., Arizona, USA
Cornwall, Wheals Muttrell and Gorland, also Wheal Unity and the Ting Tang mine, near Gwennap, England
Wheal Cock, St. Just, England
Saxony, from Schwarzenberg, Germany
Sadisdorf copper mine, near Schmiedeberg, Germany
Altväter samt Eschig mine, near Sayda, Germany

Field-hunting tip

Where it forms: A rare secondary mineral in the oxidized zone of some copper deposits. If you start seeing olivenite, chalcophyllite, clinoclase in float, you are in the right ground. Typical habit: euhedral crystals, granular. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify liroconite?+

Mohs hardness is 2-2.5. Luster: vitreous to resinous. The streak is pale blue to pale green. Common colors include sky blue, light blue, green, verdigris green.

Where is liroconite found?+

Notable localities include Sterling Hill, Ogdensburg, Sussex Co., New Jersey, and at Bisbee, Cochise Co., Arizona, USA; Cornwall, Wheals Muttrell and Gorland, also Wheal Unity and the Ting Tang mine, near Gwennap, England; Wheal Cock, St. Just, England; Saxony, from Schwarzenberg, Germany; Sadisdorf copper mine, near Schmiedeberg, Germany.

Is liroconite safe to handle?+

Liroconite contains arsenic and copper and calls for real care. Contains arsenic and copper; avoid ingestion, inhalation of dust, and wash hands thoroughly after handling specimens.

What rocks look like liroconite?+

Liroconite is most often confused with Chalcophyllite, Clinoclase, Aurichalcite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with liroconite?+

Liroconite commonly co-occurs with Olivenite, Chalcophyllite, Clinoclase, Cornwallite, Strashimirite, Malachite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does liroconite form in?+

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

What is liroconite used for?+

Liroconite is used in collector.

Find liroconite on the map

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