Kainotropite is a rare copper iron vanadate that forms iron-black to reddish black prismatic crystals. It is a sublimate at an active volcanic fumarole. It was first described from the Yadovitaya fumarole, Tolbachik Volcano, Kamchatka, Russia.

Hardness

Mohs

Luster

Vitreous

Streak

Dark Brown-red

Transparency

Opaque

mineralrare

Kainotropite

Hardness: 4
Luster: Vitreous
Streak: Dark Brown-red
Transparency: Opaque

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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 dark brown-red 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: iron-black, reddish black.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: prismatic crystals.

Often confused with

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

mineral

Antlerite

Mohs 3.5

How to tell apart: Streak differs, so Kainotropite leaves dark brown-red, Antlerite leaves light green.

How to tell apart: Streak differs, so Kainotropite leaves dark brown-red, 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: Cu₄Fe³⁺O₂(V₂O₇)(VO₄)
Mohs hardness: 4
Density: 4.104 g/cm³
Colors: Iron-black Reddish Black
Streak: Dark Brown-red
Luster: Vitreous
Transparency: Opaque
Crystal system: Orthorhombic
Crystal habit: Prismatic Crystals
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Oxidized Zones of Copper Deposits

Where rockhounds find kainotropite

Classic worldwide localities

Yadovitaya fumarole, Kamchatka, Russia

Field-hunting tip

Look in oxidized zones of copper deposits country, 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 prismatic crystals 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 dark brown-red. Common colors include iron-black, reddish black.

Where is kainotropite found?+

Notable localities include Yadovitaya fumarole, Kamchatka, Russia.

Is kainotropite safe to handle?+

It contains toxic constituents. Contains copper and vanadium, which are toxic if ingested or inhaled as dust. Wash hands thoroughly after handling and avoid creating dust. 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.