Mitscherlichite is a rare copper-potassium chloride mineral formed as a secondary deposit in volcanic fumaroles. It typically appears as small blue to blue-green prismatic or tabular crystals, often found associated with other chloride minerals in high-temperature volcanic vents.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Mitscherlichite

Hardness: 2
Luster: Vitreous
Streak: White
Transparency: Transparent

Is this mitscherlichite?

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 mitscherlichite with a known reference. Mitscherlichite sits at Mohs 2 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Mitscherlichite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Mitscherlichite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: blue, blue-green.
5
Look at form & habit
Crystal system: tetragonal. Typical habit: prismatic to tabular crystals or encrustations.

Often confused with

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

How to tell apart: Streak differs — Mitscherlichite leaves white, Tolbachite leaves yellowish red; luster reads vitreous on Mitscherlichite and subadamantine on Tolbachite.

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Often found alongside mitscherlichite

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

All properties

Chemical formula: K₂CuCl₄·2H₂O
Mohs hardness: 2
Density: 2.16 g/cm³
Colors: Blue Blue-green
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Tetragonal
Crystal habit: Prismatic to Tabular Crystals or Encrustations
Cleavage: Distinct
Rarity: Rare
Uses: Collector
Host rock: Volcanic Fumaroles
Typical price: $50-300 per specimen

Where rockhounds find mitscherlichite

Classic worldwide localities

Vesuvius (Italy)
Tolbachik Volcano (Russia)

Field-hunting tip

Look in volcanic fumaroles country — that is the host setting where mitscherlichite typically forms. If you start seeing eriochalcite, sylvite, halite in float, you are in the right ground. Field specimens usually show a prismatic to tabular crystals or encrustations habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify mitscherlichite?+

Mohs hardness is 2. It typically shows a vitreous luster. The streak is white. Common colors include blue, blue-green.

Where is mitscherlichite found?+

Notable localities include Vesuvius (Italy); Tolbachik Volcano (Russia).

How much is mitscherlichite 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 mitscherlichite safe to handle?+

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

What rocks look like mitscherlichite?+

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

What minerals are found with mitscherlichite?+

Mitscherlichite commonly co-occurs with Eriochalcite, Sylvite, Halite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does mitscherlichite form in?+

Mitscherlichite typically forms in volcanic fumaroles. Working float back to the host body is the standard way to chase a fresh occurrence.

What is mitscherlichite used for?+

Mitscherlichite is used in collector.

Find mitscherlichite on the map

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