Polkanovite is an extremely rare rhodium-arsenic mineral discovered in the Norilsk nickel-copper sulfide deposits of Russia. It typically occurs as microscopic anhedral inclusions within other platinum-group minerals or sulfide ores, making it a highly sought-after rarity for advanced mineral collectors.

Hardness

3.5

Mohs

Luster

Metallic

Transparency

Opaque

mineralrare

Polkanovite

Hardness: 3.5
Luster: Metallic
Transparency: Opaque

No image

Is this polkanovite?

4-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 polkanovite with a known reference. Polkanovite sits at Mohs 3.5, softer than the next harder reference, harder than the previous one.
2
Read the luster
Hold the specimen under a strong light. Luster: metallic.
3
Match the color range
Compare against the expected color range: gray.
4
Look at form & habit
Crystal system: hexagonal. Typical habit: microscopic crystals.

Often confused with

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

mineral

Sperrylite

Mohs 6-7

How to tell apart: Sperrylite is the harder of the two (Mohs 6-7 vs. 3.5).

Often found alongside polkanovite

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

All properties

Chemical formula: Rh₁₂As₇
Mohs hardness: 3.5
Density: 10.22 g/cm³
Colors: Gray
Luster: Metallic
Transparency: Opaque
Crystal system: Hexagonal
Crystal habit: Microscopic crystals
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: In the 0.05-1.5 mm fraction of gold-PGM-placer heavy-mineral concentrate in a river draining chromite-mineralized ophiolitic complexes (Russia)

Where rockhounds find polkanovite

Classic worldwide localities

A small unnamed placer deposit in the upper Miass River, South Urals, Russia (type locality)

Field-hunting tip

Where it forms: In the 0.05-1.5 mm fraction of gold-PGM-placer heavy-mineral concentrate in a river draining chromite-mineralized ophiolitic complexes (Russia). If you start seeing isoferroplatinum, tulameenite, native ruthenium in float, you are in the right ground. Typical habit: microscopic crystals. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify polkanovite?+

Mohs hardness is 3.5. Luster: metallic. Common colors include gray.

Where is polkanovite found?+

Notable localities include A small unnamed placer deposit in the upper Miass River, South Urals, Russia (type locality).

Is polkanovite safe to handle?+

Polkanovite contains arsenic and calls for real care. Contains arsenic, which is toxic; handle with care and avoid inhalation of dust or ingestion.

What rocks look like polkanovite?+

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

What minerals are found with polkanovite?+

Polkanovite commonly co-occurs with Isoferroplatinum, Tulameenite, Native ruthenium, Cherepanovite, Irarsite, Palladodymite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does polkanovite form in?+

Where it forms: In the 0.05-1.5 mm fraction of gold-PGM-placer heavy-mineral concentrate in a river draining chromite-mineralized ophiolitic complexes (Russia). Working float back to the host body is the standard way to chase a fresh occurrence.

What is polkanovite used for?+

Polkanovite is used in collector.

Find polkanovite on the map

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