Native osmium is an extremely dense, metallic mineral belonging to the platinum group. It is most commonly found as small, heavy, chemically resistant grains or flattened hexagonal crystals in alluvial placer deposits derived from ultramafic rocks.

Hardness

Mohs

Luster

Metallic

Streak

White

Transparency

Opaque

mineralrare

Native Osmium

Also: Iridosmine

Hardness: 7
Luster: Metallic
Streak: White
Transparency: Opaque

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Is this native osmium?

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 native osmium with a known reference. Native Osmium sits at Mohs 7 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Native Osmium leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Native Osmium typically shows a metallic luster.
4
Match the color range
Compare against the expected color range: silver-white, bluish-white, gray.
5
Look at form & habit
Crystal system: hexagonal. Typical habit: tabular crystals, rounded grains, scales.

Often confused with

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

mineral

Platinum

Mohs 4-4.5

How to tell apart: Native Osmium is noticeably harder (Mohs 7 vs. 4-4.5); streak differs — Native Osmium leaves white, Platinum leaves steel-gray.

How to tell apart: Streak differs — Native Osmium leaves white, Rutheniridosmine leaves gray.

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Often found alongside native osmium

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

All properties

Chemical formula: Os
Mohs hardness: 7
Density: 22.4-22.6 g/cm³
Colors: Silver-white Bluish-white Gray
Streak: White
Luster: Metallic
Transparency: Opaque
Crystal system: Hexagonal
Crystal habit: Tabular Crystals, Rounded Grains, Scales
Cleavage: Perfect Basal
Rarity: Rare
Uses: Collector, Scientific Research
Host rock: Platinum-group Metal Placer Deposits, Ophiolites, Ultramafic Complexes
Typical price: $500-5000+ per gram depending on purity and specimen size

Where rockhounds find native osmium

Classic worldwide localities

Ural Mountains, Russia
Chocó Department, Colombia
Bushveld Complex, South Africa
Tulameen River, Canada

Field-hunting tip

Look in platinum-group metal placer deposits, ophiolites, ultramafic complexes country — that is the host setting where native osmium typically forms. If you start seeing platinum, iridium, magnetite in float, you are in the right ground. Field specimens usually show a tabular crystals, rounded grains, scales habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify native osmium?+

Mohs hardness is 7. It typically shows a metallic luster. The streak is white. Common colors include silver-white, bluish-white, gray.

Where is native osmium found?+

Notable localities include Ural Mountains, Russia; Chocó Department, Colombia; Bushveld Complex, South Africa; Tulameen River, Canada.

How much is native osmium worth?+

Typical asking prices fall in the range of $500-5000+ per gram depending on purity and specimen size. Quality, size, and provenance can move individual specimens well outside that range.

Is native osmium safe to handle?+

It contains toxic constituents. Native osmium itself is generally inert, but exposure to air can lead to the formation of osmium tetroxide, which is highly toxic and corrosive to skin, eyes, and the respiratory system. Proper ventilation and handling techniques are essential. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like native osmium?+

Native Osmium is most often confused with Platinum, Rutheniridosmine. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with native osmium?+

Native Osmium commonly co-occurs with Platinum, Iridium, Magnetite, Chromite, Olivine. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does native osmium form in?+

Native Osmium typically forms in platinum-group metal placer deposits, ophiolites, ultramafic complexes. Working float back to the host body is the standard way to chase a fresh occurrence.

What is native osmium used for?+

Native Osmium is used in collector, scientific research.

Find native osmium on the map

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