Colinowensite is a rare copper sulfate chloride mineral discovered in the volcanic fumaroles of the Tolbachik volcano in Russia. It typically appears as small, transparent yellow tabular crystals associated with other copper-bearing volcanic minerals.

Hardness

Mohs

Luster

Vitreous

Streak

Yellow

Transparency

Transparent

mineralrare

Colinowensite

Hardness: 3
Luster: Vitreous
Streak: Yellow
Transparency: Transparent

Is this colinowensite?

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

Often confused with

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

mineral

Fedotovite

Mohs 2-3

How to tell apart: Streak differs — Colinowensite leaves yellow, Fedotovite leaves greenish-white.

Compare →

Often found alongside colinowensite

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

All properties

Chemical formula: KCu₃(SO₄)₂Cl
Mohs hardness: 3
Density: 2.8 g/cm³
Colors: Yellow Brownish-yellow
Streak: Yellow
Luster: Vitreous
Transparency: Transparent
Crystal system: Triclinic
Crystal habit: Tabular Crystals
Cleavage: Good
Rarity: Rare
Uses: Collector
Host rock: Fumarole Deposits of Volcanic Vents
Typical price: $100-500 per specimen

Where rockhounds find colinowensite

Classic worldwide localities

Tolbachik volcano, Kamchatka, Russia

Field-hunting tip

Look in fumarole deposits of volcanic vents country — that is the host setting where colinowensite typically forms. If you start seeing fedotovite, kamchatkite, tenorite in float, you are in the right ground. Field specimens usually show a tabular crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify colinowensite?+

Mohs hardness is 3. It typically shows a vitreous luster. The streak is yellow. Common colors include yellow, brownish-yellow.

Where is colinowensite found?+

Notable localities include Tolbachik volcano, Kamchatka, Russia.

How much is colinowensite worth?+

Typical asking prices fall in the range of $100-500 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

Is colinowensite safe to handle?+

It contains toxic constituents. Contains copper and chlorine; avoid ingestion or inhalation of dust. Wash hands thoroughly after handling specimens. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like colinowensite?+

Colinowensite is most often confused with Fedotovite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with colinowensite?+

Colinowensite commonly co-occurs with Fedotovite, Kamchatkite, Tenorite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does colinowensite form in?+

Colinowensite typically forms in fumarole deposits of volcanic vents. Working float back to the host body is the standard way to chase a fresh occurrence.

What is colinowensite used for?+

Colinowensite is used in collector.

Find colinowensite on the map

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