Borisenkoite is a rare copper vanadate that forms red-brown prismatic crystals. It is a sublimate at an active volcanic fumarole. It was first described from the Yadovitaya fumarole, Tolbachik volcano, Kamchatka, Russia.

Hardness

~4.5

Mohs

Luster

Greasy to adamantine

Streak

Yellowish brown

Transparency

Translucent

mineralrare

Borisenkoite

Hardness: ~4.5
Luster: Greasy to adamantine
Streak: Yellowish brown
Transparency: Translucent

No image

Is this borisenkoite?

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 borisenkoite with a known reference. Borisenkoite sits at Mohs ~4.5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: yellowish brown.
3
Read the luster
Hold the specimen under a strong light. Luster: greasy to adamantine.
4
Match the color range
Compare against the expected color range: red-brown, golden-brown, brown.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: prismatic crystals.

Often confused with

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

mineral

Lammerite

Mohs 3-4

How to tell apart: Luster reads greasy to adamantine on Borisenkoite and vitreous on Lammerite.

How to tell apart: Borisenkoite is noticeably harder (Mohs ~4.5 vs. 3); luster reads greasy to adamantine on Borisenkoite and submetallic on Dolerophanite.

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Often found alongside borisenkoite

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

All properties

Chemical formula: Cu₃(VO₄)₂
Mohs hardness: ~4.5
Density: 4.69 g/cm³
Colors: Red-brown Golden-brown Brown
Streak: Yellowish brown
Luster: Greasy to adamantine
Transparency: Translucent
Crystal system: Monoclinic
Crystal habit: Prismatic crystals
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: A sublimate at an active volcanic fumarole

Where rockhounds find borisenkoite

Classic worldwide localities

Yadovitaya fumarole, Second scoria cone, Northern Breakthrough of the Great Tolbachik Fissure Eruption, Tolbachik volcano, Kamchatka, Russia

Field-hunting tip

Where it forms: A sublimate at an active volcanic fumarole. If you start seeing sanidine, hematite, lammerite in float, you are in the right ground. Typical habit: prismatic crystals. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify borisenkoite?+

Mohs hardness is ~4.5. Luster: greasy to adamantine. The streak is yellowish brown. Common colors include red-brown, golden-brown, brown.

Where is borisenkoite found?+

Notable localities include Yadovitaya fumarole, Second scoria cone, Northern Breakthrough of the Great Tolbachik Fissure Eruption, Tolbachik volcano, Kamchatka, Russia.

Is borisenkoite safe to handle?+

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

What rocks look like borisenkoite?+

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

What minerals are found with borisenkoite?+

Borisenkoite commonly co-occurs with Sanidine, Hematite, Lammerite, Lammerite-β, Bradaczekite, Zincobradaczekite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does borisenkoite form in?+

Where it forms: A sublimate at an active volcanic fumarole. Working float back to the host body is the standard way to chase a fresh occurrence.

What is borisenkoite used for?+

Borisenkoite is used in collector.

Find borisenkoite on the map

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