Kainotropite is an extremely rare copper sulfate mineral found as a secondary mineral in oxidized ore deposits. It typically forms small, dark green tabular crystals that are difficult to distinguish from associated copper minerals without rigorous chemical testing or X-ray diffraction.

Hardness

Mohs

Luster

Vitreous

Streak

Light Green

Transparency

Translucent

mineralrarenull family

Kainotropite

Hardness: 4
Luster: Vitreous
Streak: Light Green
Transparency: Translucent

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Is this kainotropite?

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 kainotropite with a known reference. Kainotropite sits at Mohs 4 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Kainotropite leaves a light green streak.
3
Read the luster
Hold the specimen under a strong light. Kainotropite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: dark green, black, olive green.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: tabular crystals, crusts.

Often confused with

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

How to tell apart: Streak differs — Kainotropite leaves light green, Brochantite leaves pale-green.

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Often found alongside kainotropite

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

All properties

Chemical formula: Cu₄(SO₄)(OH)₆
Mohs hardness: 4
Density: 4.15 g/cm³
Colors: Dark Green Black Olive Green
Streak: Light Green
Luster: Vitreous
Transparency: Translucent
Crystal system: Orthorhombic
Crystal habit: Tabular Crystals, Crusts
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Oxidized Zones of Copper Deposits
Typical price: $50-300 per specimen

Where rockhounds find kainotropite

Classic worldwide localities

Chuquicamata Mine (Chile)

Field-hunting tip

Look in oxidized zones of copper deposits country — that is the host setting where kainotropite typically forms. If you start seeing antlerite, brochantite, chalcanthite in float, you are in the right ground. Field specimens usually show a tabular crystals, crusts habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify kainotropite?+

Mohs hardness is 4. It typically shows a vitreous luster. The streak is light green. Common colors include dark green, black, olive green.

Where is kainotropite found?+

Notable localities include Chuquicamata Mine (Chile).

How much is kainotropite worth?+

Typical asking prices fall in the range of $50-300 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

Is kainotropite safe to handle?+

It contains toxic constituents. Contains copper which is toxic if ingested or inhaled as dust; wash hands thoroughly after handling. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like kainotropite?+

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

What minerals are found with kainotropite?+

Kainotropite commonly co-occurs with Antlerite, Brochantite, Chalcanthite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does kainotropite form in?+

Kainotropite typically forms in oxidized zones of copper deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is kainotropite used for?+

Kainotropite is used in collector.

Find kainotropite on the map

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