Nicksobolevite is a rare copper selenite chloride mineral discovered in the volcanic fumaroles of the Tolbachik volcano. It typically forms as thin, platy crystals with a distinctive deep violet to blue color and is highly prized by mineral collectors specializing in rare volcanic species.

Hardness

2-2.5

Mohs

Luster

Vitreous

Streak

Orange-red

Transparency

Transparent

mineralrare

Nicksobolevite

Hardness: 2-2.5
Luster: Vitreous
Streak: Orange-red
Transparency: Transparent

No image

Is this nicksobolevite?

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 nicksobolevite with a known reference. Nicksobolevite sits at Mohs 2-2.5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: orange-red.
3
Read the luster
Hold the specimen under a strong light. Luster: vitreous.
4
Match the color range
Compare against the expected color range: dark red.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: platy crystals.

Often confused with

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

mineral

Chalcomenite

Mohs 2-2.5

How to tell apart: Streak differs, so Nicksobolevite leaves orange-red, Chalcomenite leaves light blue.

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Often found alongside nicksobolevite

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

All properties

Chemical formula: Cu₇(SeO₃)₂O₂Cl₆
Mohs hardness: 2-2.5
Density: 4.18 g/cm³
Colors: Dark red
Streak: Orange-red
Luster: Vitreous
Transparency: Transparent
Crystal system: Monoclinic
Crystal habit: Platy crystals
Cleavage: Perfect on {010} and {1̄01}, good on {120}
Rarity: Rare
Uses: Collector
Host rock: In crusts deposited from gases escaping an active fumarole on a basaltic volcano

Where rockhounds find nicksobolevite

Classic worldwide localities

Tolbachik volcano, Kamchatka Peninsula, Russia

Field-hunting tip

Where it forms: In crusts deposited from gases escaping an active fumarole on a basaltic volcano. If you start seeing chloromenite, prewittite, melanothallite in float, you are in the right ground. Typical habit: platy crystals. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify nicksobolevite?+

Mohs hardness is 2-2.5. Luster: vitreous. The streak is orange-red. Common colors include dark red.

Where is nicksobolevite found?+

Notable localities include Tolbachik volcano, Kamchatka Peninsula, Russia.

Is nicksobolevite safe to handle?+

Nicksobolevite contains copper and selenium. Contains copper and selenium; handle with care, do not ingest, wash hands thoroughly after handling and avoid inhaling dust.

What rocks look like nicksobolevite?+

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

What minerals are found with nicksobolevite?+

Nicksobolevite commonly co-occurs with Chloromenite, Prewittite, Melanothallite, Sophiite, Ralstonite, Ponomarevite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does nicksobolevite form in?+

Where it forms: In crusts deposited from gases escaping an active fumarole on a basaltic volcano. Working float back to the host body is the standard way to chase a fresh occurrence.

What is nicksobolevite used for?+

Nicksobolevite is used in collector.

Find nicksobolevite on the map

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