Conichalcite is a vibrant green secondary mineral often found as attractive botryoidal or crust-like coatings on rock surfaces. It forms in the oxidized zones of copper-arsenic deposits and is frequently collected for its bright coloration and pleasing globular habits.

Hardness

4.5

Mohs

Luster

Vitreous

Streak

Light Green

Transparency

Translucent

mineralcommon

Conichalcite

Hardness: 4.5
Luster: Vitreous
Streak: Light Green
Transparency: Translucent

Is this conichalcite?

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 conichalcite with a known reference. Conichalcite 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. Conichalcite leaves a light green streak.
3
Read the luster
Hold the specimen under a strong light. Conichalcite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: green, yellow-green, emerald-green.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: botryoidal, druzy, massive, or crusts.

Often confused with

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

mineral

Austinite

Mohs 4

How to tell apart: Streak differs, so Conichalcite leaves light green, Austinite leaves white.

How to tell apart: Conichalcite is noticeably harder (Mohs 4.5 vs. 3); streak differs, so Conichalcite leaves light green, Olivenite leaves olive-green; luster reads vitreous on Conichalcite and adamantine on Olivenite.

Often found alongside conichalcite

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

All properties

Chemical formula: CaCu(AsO₄)(OH)
Mohs hardness: 4.5
Density: 4.1-4.3 g/cm³
Colors: Green Yellow-green Emerald-green
Streak: Light Green
Luster: Vitreous
Transparency: Translucent
Crystal system: Orthorhombic
Crystal habit: Botryoidal, Druzy, Massive, Or Crusts
Cleavage: None
Rarity: Common
Uses: Collector, Mineral Specimen
Host rock: Oxidized Zones of Arsenic-rich Hydrothermal Copper Deposits
Typical price: $10-100 per specimen depending on quality and matrix

Where rockhounds find conichalcite

Classic worldwide localities

Gold Hill, Utah, USA
Mapimi, Durango, Mexico
Tsumeb, Namibia
Bisbee, Arizona, USA
Chile

Field-hunting tip

Look in oxidized zones of arsenic-rich hydrothermal copper deposits country, the host setting where conichalcite typically forms. If you start seeing malachite, limonite, adamine in float, you are in the right ground. Field specimens usually show a botryoidal, druzy, massive, or crusts habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify conichalcite?+

Mohs hardness is 4.5. It typically shows a vitreous luster. The streak is light green. Common colors include green, yellow-green, emerald-green.

Where is conichalcite found?+

Notable localities include Gold Hill, Utah, USA; Mapimi, Durango, Mexico; Tsumeb, Namibia; Bisbee, Arizona, USA; Chile.

How much is conichalcite worth?+

Typical asking prices fall in the range of $10-100 per specimen depending on quality and matrix. Quality, size, and provenance can move individual specimens well outside that range.

Is conichalcite safe to handle?+

It contains toxic constituents. Contains arsenic and copper; avoid dust inhalation and wash hands thoroughly after handling. Keep away from food and children. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like conichalcite?+

Conichalcite is most often confused with Austinite, Olivenite, Malachite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with conichalcite?+

Conichalcite commonly co-occurs with Malachite, Limonite, Adamine, Duftite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does conichalcite form in?+

Conichalcite typically forms in oxidized zones of arsenic-rich hydrothermal copper deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is conichalcite used for?+

Conichalcite is used in collector, mineral specimen.

Find conichalcite on the map

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