Kashinite is an extremely rare iridium sulfide mineral typically found as microscopic grains in alluvial platinum deposits. Because of its rarity and size, it is strictly a professional research or advanced private collector species that requires micro-analysis for positive identification.

Hardness

7.5

Mohs

Luster

Metallic

Streak

Gray

Transparency

Opaque

mineralrare

Kashinite

Hardness: 7.5
Luster: Metallic
Streak: Gray
Transparency: Opaque

Is this kashinite?

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 kashinite with a known reference. Kashinite sits at Mohs 7.5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: gray.
3
Read the luster
Hold the specimen under a strong light. Luster: metallic.
4
Match the color range
Compare against the expected color range: gray, black.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: anhedral grains.

Often confused with

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

mineral

Laurite

Mohs 7.5

How to tell apart: Streak differs, so Kashinite leaves gray, Laurite leaves dark gray.

How to tell apart: Kashinite is noticeably harder (Mohs 7.5 vs. 4-5); streak differs, so Kashinite leaves gray, Cooperite leaves black.

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Often found alongside kashinite

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

All properties

Chemical formula: Ir₂S₃
Mohs hardness: 7.5
Density: 9.1 g/cm³
Colors: Gray Black
Streak: Gray
Luster: Metallic
Transparency: Opaque
Crystal system: Orthorhombic
Crystal habit: Anhedral grains
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: In placer deposits derived from ultramafic rocks

Where rockhounds find kashinite

Classic worldwide localities

Goodnews Bay, Alaska, USA
Aleksandrov Log platinum deposit, Mt. Solov’eva, Nizhni Tagil massif, Ural Mountains (type locality), Russia
Ray-Iz ophiolite complex, Polar Ural Mountains, Russia
Vaimka River placers, Aluchinskii massif, and the Baimka placers, Aluchin horst, Chukota region, Far Eastern Region, Russia
Chromwerk, Kraubath ultramafic massif, Styria, Austria

Field-hunting tip

Where it forms: In placer deposits derived from ultramafic rocks. If you start seeing iridosmine, platinum, osmiridium in float, you are in the right ground. Typical habit: anhedral grains. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify kashinite?+

Mohs hardness is 7.5. Luster: metallic. The streak is gray. Common colors include gray, black.

Where is kashinite found?+

Notable localities include Goodnews Bay, Alaska, USA; Aleksandrov Log platinum deposit, Mt. Solov’eva, Nizhni Tagil massif, Ural Mountains (type locality), Russia; Ray-Iz ophiolite complex, Polar Ural Mountains, Russia; Vaimka River placers, Aluchinskii massif, and the Baimka placers, Aluchin horst, Chukota region, Far Eastern Region, Russia; Chromwerk, Kraubath ultramafic massif, Styria, Austria.

What rocks look like kashinite?+

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

What minerals are found with kashinite?+

Kashinite commonly co-occurs with Iridosmine, Platinum, Osmiridium, Laurite, Erlichmanite, Cuproiridisite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does kashinite form in?+

Where it forms: In placer deposits derived from ultramafic rocks. Working float back to the host body is the standard way to chase a fresh occurrence.

What is kashinite used for?+

Kashinite is used in collector.

Find kashinite on the map

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