Dunite is an ultramafic plutonic rock composed almost entirely of olivine. It is typically found in ophiolite complexes and often shows significant alteration into serpentinite, making fresh, solid samples a prized find for rockhounders interested in mantle petrology.

Hardness

6.5-7

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

igneouscommonOlivine Group family

Dunite

Hardness: 6.5-7
Luster: Vitreous
Streak: White
Transparency: Translucent

Is this dunite?

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 dunite with a known reference. Dunite sits at Mohs 6.5-7 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Dunite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Dunite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: yellow-green, olive-green, dark green.
5
Look at form & habit
Typical habit: massive.

Often confused with

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

igneous

Peridotite

Mohs 6-7

How to tell apart: Luster reads vitreous on Dunite and vitreous to dull on Peridotite.

How to tell apart: Dunite is noticeably harder (Mohs 6.5-7 vs. 2.5-5.5); luster reads vitreous on Dunite and waxy on Serpentinite.

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Often found alongside dunite

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

All properties

Mohs hardness: 6.5-7
Density: 3.2-3.4 g/cm³
Colors: Yellow-green Olive-green Dark Green
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal habit: Massive
Cleavage: None
Rarity: Common
Uses: Industrial, Collector, Geological Study
Host rock: Mantle Rocks
Typical price: $5-30 specimen

Where rockhounds find dunite

Classic worldwide localities

Dun Mountain, New Zealand
Twin Sisters Mountains, USA
Troodos Ophiolite, Cyprus
Norway
Canada

Field-hunting tip

Look in mantle rocks country — that is the host setting where dunite typically forms. If you start seeing olivine, chromite, pyroxene in float, you are in the right ground. Field specimens usually show a massive habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify dunite?+

Mohs hardness is 6.5-7. It typically shows a vitreous luster. The streak is white. Common colors include yellow-green, olive-green, dark green.

Where is dunite found?+

Notable localities include Dun Mountain, New Zealand; Twin Sisters Mountains, USA; Troodos Ophiolite, Cyprus; Norway; Canada.

How much is dunite worth?+

Typical asking prices fall in the range of $5-30 specimen. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like dunite?+

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

What minerals are found with dunite?+

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

What kind of rock does dunite form in?+

Dunite typically forms in mantle rocks. Working float back to the host body is the standard way to chase a fresh occurrence.

What is dunite used for?+

Dunite is used in industrial, collector, geological study.

Find dunite on the map

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